Wife very difficult to along with, thinking of the D

First a little background: I've been married about 15 years. I have a well paying job for which I travel about 10 days/month and the rest of the time I'm waking kids up for school, helping with homework, taking kids to sports practices, I even cook most meals. My wife works in the medical field 2-4 days/ week at most though it's not necessary for our finances. I've been supportive to her career going so far as agreeing to move to a different state so that she'd have better career options. My job pays the bills, saves for retirement, has the health insurance, etc.; hers pays for remodeling the house, buying some new (used) cars, things like that. All this to say that we have what I consider to be a very fortunate existence with very little struggle and stress compared to a lot of people.

Now to the root of the problem. I find my wife to be very rude, hypocritical, demeaning, insulting, you name it. I am very limited in topics I care to discuss with her because she simply can not bear to have me disagree with her on anything. I can't ask her simple questions because they are either too trivial, or something I should have already known. She will take any opportunity to ram anything I've ever done wrong in my face. She's rude on a daily basis, making dozens of little digs against me. I typically ignore it all until it blows up, or else we'd be arguing constantly.

Examples: I told the kids to take a hot bath/shower after a sports practice in an area where I'd suffered a lot of chigger bites. She basically told me that I'm an idiot and that would do nothing. For my own education, I looked up the topic and found a paper written by state college PhD entomologists who held the opposite opinion. I held this info close to my chest for weeks, because I simply don't want to start fights. When we finally had one of our monthly screaming contests I brought this up as an example of how she's not always right and can't bear to be wrong. Then the topic changed to how I am at fault for not blindly agreeing with her and how I am always trying to prove her wrong. (I was perfectly willing to sit on this knowledge re: chiggers forever, I don't feel the need to correct her, especially if it leads to a knock-down drag-out).

There are cases when I have to travel on fairly short notice when she's already committed to work. We have (her) family close by to watch the (elementary aged) kids, and we live in a neighborhood with plenty of babysitters. Whenever I travel I get text messages about how inconsiderate I was not to empty the dishwasher before I left (even though I woke up and took the kids to school early that morning before I left, and she had the whole day off), how I'm a jerk for not getting cash for the babysitter (even though she has a checkbook and is/should be perfectly capable of getting money from an ATM). Every minor mistake or oversight is a perfect reason to be a total bitch to me, even if she knows I'm busy. (But heaven forbid if I try to contact her when she's at work)

When I finally began a fitness regimen, started lifting weights and watching my diet, far from showing any encouragement, she ridiculed me for trying to be a "muscle head". She made a very dramatic point of telling me a story (possible untrue) about a coworker's husband who was gravely ill due to a stroke from whatever he was taking for his bodybuilding hobby. The strongest thing I ever took was a protein shake, nothing like testosterone, stimulants, HGH, etc., but my wife always relies on hyperbole to try to humiliate me.

It's been impossible to visit my family for vacation, but we always have time to go to Mexico (her favorite, 3 times in the last few years and another visit coming up) or to see her family. I'm glad to see her family, especially for something like her grandmother's funeral this past summer, but there's never a chance to see my parents. Last time was about 5 years ago.

In fairness, I have not been perfect. I've bought things without her knowledge. I've gone around her because I simply wanted to avoid the fight. A few years ago I lost a job for, in my opinion, standing on my moral principles after my previous employer was bought out. (This was an incredibly stressful time for me and I couldn't feel that I could share what was happening behind the scenes with her because I didn't think she'd be helpful. I pretty much accepted that she'd leave me when that situation finally came to a head.)

Every few weeks something will set her off and she will go into an absolute screaming shitfit against me; she'll call me names, make all kinds of accusations, bring up every time I've ever offended her. One time I videoed her with my phone because I legitimately felt that I'd need some kind of evidence of her behavior. She smashed my previous MacBook on the ground, I think breaking something on the motherboard.

Some background info on her: She comes from a broken home where her dad came out as gay and her mom and brother are staunch Catholics. She has few friends, finds fault with everyone, our school, our neighborhood, my friends, my family, you name it. She is a younger sibling of a brother who is not as successful professionally as she is, but I think she still felt overshadowed somehow. She constantly has to remind me and pretty much everyone of her glory days of being a high GPA student, being accepted in a rigorous degree program for a competitive field, and makes a great show of whenever an opportunity comes to show off her knowledge. (Actually, I'm proud of her in this regard, I always found her success to be attractive.)

We've been to counseling in the past but I'm not attracted to this option anymore. It becomes a "beat up letak" session and she even ridicules opinions that I've expressed in counseling. For instance, I once described my family growing up as "very Beaver Cleaver" because it was fairly close to that: Dad worked a lot in a well-paid professional job, mom was a homemaker, similar family dynamics with minor trouble here and there, but overall not a lot of drama. She thought I was trying to "suck up" to the counselor or make her look bad or whatever. I know I've got my issues about opening up to people. I compartmentalize my life. I feel comfortable telling certain people certain things. She sees this as being deceptive. She also calls me a narcissist, which I find really rich because I am very empathetic and don't have a need for people to agree with me, even though I enjoy a healthy debate, nor do I worry about my appearance too much or try to manipulate people. As a matter of fact I feel like she manipulates me with rage outbursts.

Basically I'd leave yesterday if it wasn't for the kids. I still get a rush of something the times that she's nice to me, or even civil, really, but most of the time I dread being around her. I can't help but wonder if I'm in some kind of abusive relationship. I'm the kind of guy who can take a lot of shit, roll my eyes, ignore it, and keep going...

Edit:

So what am I dealing with here? I don't feel like this is normal, but is it that bad in the grand scheme of things? Am I undergoing some kind of abuse?

I should mention that I feel like she bullies her father. She calls him by his first name (he doesn't seem to mind but I think it's weird), she talks over him, always shows impatience.

Edit#2: I know this is way past long, but I feel like it's important: She's always very willing to criticize or point out faults rather than actually fix something. Whenever she does household chores it's always as if she can't believe I haven't done something already and it's a major inconvenience for her to have to mop or put away dishes. I may not clean or vacuum or do a particular chore as frequent as she'd like but when I do it I don't act as if I'm suffering an injustice. I just do it. When she puts away dishes she seems to go out of her way to clang dishes together to make noise. If we need something from the grocery store it's always my fault that it wasn't picked up before. It's really an endless list of petty and argumentative behavior.