It's sort of a long story, so I'll try to summarize best I can. I have lurked seddit for over a year now but never really posted. Here's why:

I began dating my current girlfriend 5 years ago. We are both currently 21. She is beautiful, kind hearted, intelligent, and an overall wonderful person, she is by all definitions a 10. No bullshit, no bias, she is a serious catch. I honestly don't know how or why I've been in this relationship so long, but it has almost always been a good one. We mesh together well; she is my dream girl.

Here's the problem, about a 2 years ago my father died unexpectedly in an accident, and I ended up breaking up with her because I wasn't handling his death well and fell into a spiral of depression. During that time is when I met seddit, and began self improvement. About 6 months in, I was just getting my confidence back, my sense of independence, slowly ridding oneitus, settling in to being single. Then, we met up for coffee one day and ended up getting back together within 20 minutes. It felt so good being with her again, I remember it like it was yesterday. That was roughly a year and half ago.

I know this seems like a relationship thing, but the backstory was necessary. Here's where you come in:

I am torn between being with my girlfriend and breaking things off to pursue the unknown. She is amazing, and I could see myself spending the rest of my life with her. But at the same time, I find myself thinking about other women. Our relationship is suffering because I am having doubts. I know if I worked at it our relationship would be perfect. But I have so many insecurities about being single. I've only had sex with 2 girls (it shouldn't matter and I know that but it feels like it does....). I don't know what flirting or courtship really even feels like anymore. I know a bunch of one night stands won't really satisfy me, but I desperately crave that experience. I want to explore, but I don't want to lose the woman I love forever (maybe just temporarily... I realize how terrible that sounds but I'm being real with you guys). We've talked about a break, but she isn't into that. And she said if we were to break up she doesn't ever see us getting back together, it would be too hard to lose me twice is what she said. She is fully committed in this relationship. She is willing to put in the effort to make it work, and she is always positive and encouraging with me. This is why this is such a tough decision. I am happy, but I do not feel fully satisfied, even though I have everything I could ever want in a relationship already.

Anyone have any experience, stories, or wisdom, they would care to pass on to me? I love this woman and could spend my life with her, but I often contemplate being single and what meeting other girls is like.

Stuck at a crossroads; hoping someone out there will read the mountain I posted and issue some kick ass life advice.

EDIT: Thanks for being the blunt dickheads you are, while still providing a new perspective. I really needed this. Going to take most everyones advice here and focus on what's in front of me.