Overcoming past paranoia

OK long posts suck so I'll try make this short, err, simple at least. I posted this elsewhere but an oncoming migraine mutilated it. This isn't like me so err..

So my friend Thomas and I like each other, which is good. Finally it's mutual 'cause we got closer again I started liking him too. >.>

([b]history[B]) My last relationship was bad , lasted two years. I became emotional, miserable, oversensitive and was treated horribly by the guy/BOY. I became obsessed with fixing him and the relationship, he lost interest in me lots of times but I was stupid enough to tolerate his nasty changes and it took me a while to get over him when he left for good.

Anyway I've been amazingly happy since getting over last guy. Thomas was one of the friends there for me through the bad relationship, so he knows what happened with the last guy. (He liked me all this time) So he understands the effects that relationship had on me; I lack affection, fail at seriousness and get scared history will repeat itself. While he understands, he also (like me) isn't generous with tolerating the past as an excuse...

It's beginning to show. I suppose this could be delayed frustration at how cold and difficult I used to be. Nonetheless he still likes me. We JUST got past my inability to tell him I like him, so that's one hurdle. I also stopped being "aggressive" and harsh jokey-wise with him. If I can't show affection, I can at least not be harsh, right? He says he likes affection and only stopped showing it to me so much because I somewhat berated his affection/compliments. I've stopped doing this but I suppose it wasn't soon enough, it's all built up.

Maybe his frustration is beacuse he's on a trip right now for a few months. But I'm getting somewhat paranoid, and sometimes assume Thomas is losing interest in me, even if he acts different for a few days or shows less affection. i.e. Overthinking. He snapped at me a lot this week, and was extremely irritable, so that was a bit like a flashback and threw me. We've had a few "talks/arguments" where he approaches a problem, then if I don't respond how I guess he wants me to, he gets mad and gets all "This is why I don't try to approach problems between us. It takes hours just to get to the issue. Feel like I need to write up a report" and such. I want to discuss issues if it'll help us communicate or whatever it is.

(problem) I suck at being direct/serious, probably because I don't want to be how I was in the last relationship. I really don't want to mess this thing up or jynx it with previous issues, but I'm equally terrified of being let down again. I hate emotions, and that I'm suddenly feeling this sort of connection again. Even subconsciously it feels like my mind's working against me. :[ I want to nip all these confusing issues/emotions in the bud.

I'm feeling vulnerable since his little snaps at me, too. Like I shouldn't have stopped being mean, because now when he snaps or lacks affection I feel weaker somehow, like I felt in my past relationships. Over the years I suppose I've lost faith in guys, but while I know that's not fair to Thomas I also can't shake it. My trust sort of hangs on a thread, and my mind goes crazy when I think it might snap. =/ I keep expecting him to disappear like the last guy, or hurt me that way.

Any ideas or suggestions, related experiences, I'd like to hear some thoughts. Sorry for sounding like a teenaged drama queen.

Thank you lots.