NAH.

You're having an emotional reaction, and having an emotional reaction doesn't make you the a-hole. The way you're handling your emotional reaction is what makes you the A or not. Here you're handling it just fine - removing yourself from situations which are making you uncomfortable, and taking responsibility for your share of the problem.

I don't think your friends are the A either, here, although that's a little harder to define, since they didn't pick up your cues (not entirely your fault) and misinterpreted how much their jokes were upsetting you. Certainly a quick apology and all should be forgiven, or even just letting it drop should be fine.

It's one of those really weird things about the way guys tend to socialize in groups, particularly when you're under 25 or so, is that a certain amount of ripping on each other is just sort of expected, and you should work on your ability to laugh it off because, most of the time, none of it is really serious. But the nature of that kind of banter is that every so often somebody touches a sensitive spot.