At first she was crazy attracted to me. If I texted her to come over to my apartment she would be over in minutes. We had sex multiple times a week. We were both super happy and everything was great.

An overwhelming majority of the time, attraction wanes and does not reach the level it was once at. Better to accept this as a fact of life than to set out on a quest to do whatever it takes to revive it once this happens again (and it very likely will).

Tonight I got her to come over and I told her what I expected out of this relationship. All I asked for was to hang out a few times a week and at least have sex once a week. I then asked her why she stopped wanting to have any physical intimacy with me.

Read Rollo's piece titled "Just Get It" and "The Desire Dynamic". Women want guys who just get it, who understand how the game works, and they cannot be negotiated into 'producing' mechanically (i.e. spreading her legs) for the sake of a relationship, especially one in critical condition (perhaps already dead, only you failed to read the signs, possibly because you didn't know what to look for in the first place). Truth is, even if she agreed to let you tap that ass a very modest once a week, the resentment would have only exponentially grown with each passing session. Tying together her feelz (or lack thereof) with the responsibility of putting out is a ticking time bomb in the making. This is precisely why we constantly tell others around here to NEVER GET MARRIED, because should you find yourself in this situation within a marriage, you almost certainly ain't going nowhere without getting a serious beating (financial) first (think of gangs nice enough to simply have a few other members pummel you for a few minutes instead of killing you in order to defect from the gang). By the way, there are about 34,896 other reasons to get married, but I digress...

She told me that it's not that she's not attracted to me ( I never asked if that was the reason) or anything like that.

Women always try to save face, even when caught red-handed ("you forced me to cheat on you! It's your fault!") Don't hate them for it, just learn to read them better ("listen to her actions, not her words")

Her reasoning was that she had sex so much because she was trying to get me to commit to her and now that she has me she no longer needed to behave that way.

Hmmm. A little surprising she'd come right out and admit that, but consider it a loud and clear warning shot. You now know what you're dealing with (or dealt with, rather). Anything else going wrong between you and her falls squarely on your shoulders now.

I told her I have no interest being with anyone that thinks that way and that she should leave. Fuck. Yes. I feel so much better.

Good job. I've been there before, and yes, it takes balls to do what you did, particularly if you have little or no knowledge of TRP and could have been colored a typical blue-piller. Things will begin to get much better from here on out if you stick with the wise counsels found around these here parts.

On a side note, how can I prevent this from happening in the future? I really liked her. She told me she used to have sex with her ex she dated 3-5 times a week. Somehow she never wanted to touch me. I'm a pretty damn good looking dude and have never ran into this issue before.

Begin with readjusting the crosshairs belonging to your concerns. Remove them from your dating life and aim them square at yourself. Change the question(s). Start caring about YOU a billion times more. "How do I grow stronger?" "How do I get better at what I do?" "How do I become interesting?" "How do I learn to enjoy my own company?" These are a handful of questions that ought to tower above concerns that reek of "the one". You already made the first bold move (breaking up with this succubus), and a damn good one too. Tread down this path of achievement-based self-love and with enough persistence, perseverance, and determination, you'll never again have it "happen in the future".