BazzMann's Relationship problem - advice required
Okay, I've been going out with my girlfriend for 9 months, and on the whole it's been a truely perfect relationship. Our personalities compliment eachother so well, we make eachother laugh, every time we go somewhere it is always fun to be with her, and we seem to be at ease at communicating with eachother, for the most part, socially, sexually and otherwise.
However, I found out a couple of months ago that she had kissed another guy within the first few weeks of me going out with her. This guy she kissed was an ex who she had a history with, who I was actually enemies with at the time anyway. Even though it was so in the past, i found out a couple of months ago, and it really hurt and upset me. I hate cheating, and I've never done it myself - I'm not sure why I make such a big deal about it, but I do. And I expect my partners to understand that. I've been cheated on in the past, and it's not nice... anyway, this happened, and I found out, not through her. i guess the main thing that hurt me was finding out from someone else.
Anyway, we talked about it, and I agreed to forgive her and work again, providing that she was totally honest with me about EVERYTHING - she's honest usually about most things, but the things that actually truely matter in relationships, she wasn't being honest. She swore to me that it'd never happen again, etc. Anyway, more recently, about a month ago, I started getting a weird feeling, and I did something shitty that I never used to do. I checked up on her, i.e. her emails, etc. - and found chatlogs of her camming with another guy. This guy was some random guy she knew, and it didn't really get exceptionally far, but when I found it out and asked her, she lied again. I admitted going through her stuff and everything... anyway, we talked about that, and were soooo close to breaking up, but managed to survive it.
We both agreed to be more honest, me when I get suspicious (i.e. talking rather than spying) and her for owning up to mistakes, and actually not making them. Well, it's very recent and we have had a few arguments over the same old things. No matter what I do, I can't help getting weirdly jealous and paranoid about certian things - I feel like 2 different people. A part of me is as I always was; trusting, compassionate, understanding - yet this other part of me sometimes hits me like a wave. I become jealous over nothing, and I get this huge emotion of sadness hit me, which causes me to tell my girlfriend. I've never been a posessive, controlling boyfriend - and my worst fear is turning into one.
So I'm wondering whether this is just a case of mistrust that will heal, or maybe just the aftereffects of hurt that will get better in time - or is there something deep-rooted inside me that is incapable of ever regaining my trust? I know you aren't equipped to answer these questions for me, but I'd appreciate some sort of feedback, at least maybe some sort of shared experiences from those who've had similar experiences. Even if you say "dude, it isn't even a big thing, why you being such a dickwipe?" - at least it's something. The only thing I'm 100% sure about is how my girlfriend feels about me - I know she loves me and wants to be with me; that isn't questionable. I just can't understand why these problems come up.