Okay so recently my girlfriend of two years broke up with me and it was in part to a argument we had. We worked it out, but then she started seeing this other guy and just dumped me a few days later. I've heard of women who come from broken families (I.E. Divorced Parents, alcoholic mom)tend to self destruct on relationships, just find some way out of a relationship because of the commitment. Her reason for breaking up with me was because I stressed her out the only reason she ever said she was stressed was because I wasn't always organized, and couldn't keep a super clean apartment.

Now the reason I don't believe the stressed part is because her new boyfriend is a guy who works at a gas station, lives in a trailer with his mom and doesn't own a car, basically all the cleanliness problems I have he is about 10x worse.

I'm wondering if there is something I'm missing or if someone else has been in a relationship that they thought was working wonderfully and just ended.

It's a very common phenomenon with women that they get upset about something small when it's really something else that's scraping their emotions raw. On the other hand, it's also common that years of small things in the same person without any change or improvement can slowly wear away at compassion and affection. I don't know your girlfriend, but I can tell you that the chances that it was completely her issues with nothing you could have done are slim to none in a relationship that long. There are few relationships from which we have nothing to learn but the fecklessness of others.

It sounds like, for example, that you don't know your girlfriend of two years well enough to make more than a vague generalized guess at her motivations. It also sounds like you were seeking out commitment in the relationship, and hadn't really addressed it with her thoroughly. Cooperation and accord aren't something that come naturally between two people. They come with lots of arguments. Plenty of hashing out. To me, it sounds like she didn't want to go through these steps with you. This could be a number of things on her part: fear, lack of trust, silent resentment, and many other things. Or it could have been as simple as she couldn't see herself with you in the long-term. I recommend when you move on to a new relationship you try and figure out how you might address these things if they're present. How you might stay on the same page as a couple as to where you are and where you want to go. A couple should be a team that seek to accomplish goals together. Build something. Not simply maintain, or avoid the worst of the arguments and pet-peeves.

He's probably better in bed. Smiles differently. Says something else... Whatever.
Basically she sees him currently as an improvement over something she knows.

And you're over thinking it. As much as we would like to... Rarely do we get the ex back when we fix the reason they give us for leaving. We only get the ex back sometimes. And usually after a year or two have passed, and we've grown. And they've made a few choices they regret.

Sounds like the usual relationship problem, people get bored (no your organization had nothing to do with it she just needed some justification).
Not everyone works together well, especially not in the long run so after a couple of years it might just feel like more work then fun and that is usually the point people look for greener pastures.

What does the new guy have that you don't? He is new, that is all she looks for right now.
And honestly you should too, if she got tired of everything then that relationship would just get progressively worse and bitter, now imagine you got married before you discovered this... hell on earth is what that would be.
So go out and meet someone that can keep the flames alive with you.

Thank you all for the advice. I didn't mean to try and generalize the issue initially but I wanted to keep it short seeing as this is my first post in Advice. Again thank you all for the advice, it has helped me realize some things and helped me move on.