Negative reactions from people?

Newcomer here. Hello everyone.

Here's my story - in the next post I'll tell of the main problem I have that is driving me deeper into avoidant behavior.

First of all, I don't think I have AvPD, at least not yet. I can still function in social situations, but there's a major problem. Lately, though, I've been getting worse. My university doesn't enforce attendance, so I almost completely stopped going there. My procrastination problem has also been getting worse.
My main social problem fits with this thread. Not only do I believe everybody hates me, but I also belief that the former is true. I know everyone in school hated me and frankly, they had a reason to. I have a condition called Kallman's Syndrome - because of it I lack a sense of smell. I don't know why, but my parents never bothered to teach me anything about personal hygiene, so I only showered once a week until I was 17. After that I had to live with my older brother who flat out told me after the first week that I stink and need to shower more often.
I entered university thinking it would be different. And it was during the first year - everybody moved out of their parents' homes, I rented an apartment with my brother, a few of my school friends (the few people who tolerated me in school) rented a place just a couple of blocks away from us and as time went by we grew closer, we were actually friends. I still had trouble getting along with people, but the fact that I had people who appreciate me and care about me (we used to help each other out a lot and would hang out almost every day) made me happy. 2006 was the happiest year in my life.
Then it went downhill. My friends got kicked out of their apartment and had to move to different far-off locations, meeting became difficult and my already strained relationship with my brother (he has a lot of issues himself) began to deteriorate - he would abuse me and insult me all the time. He would attack me physically and, even though I'm stronger than him, would always threaten to use his powerful friends (some of his friends are influential people) to put me in jail for beating him up. He threatened to do that even when I just grabbed his hands to stop him from hitting me. In the end I became bitter and angry and eventually forced him to move out, but the damage had already been done - I had been his doormat for almost two years at that point.
Right now I'm almost completely alone. I maintain a superficial connection with my school friends and have a few people I sometimes talk to online and that's it.

Here's my main problem in social situations: I believe nobody likes me. That's common in AvPD, right? Well, I used to think that even when I was happy, but my rationalizing mind told me that there's no way EVERYBODY could react negatively to me. In the past several months, however, I've come to believe that, however bizarre, this is actually true. Everyone I meet reacts either with repulsion or contempt. Even animals attack me and small children become scared. I hardly ever participate in group discussion and when I do (sometimes I have to if the decision is going to affect me directly) my opinion is always immediately dismissed. It's not exaggeration - the usual response I get from anyone is "Oh, shut up, Karl". And it's not even like I come up with crazy ideas or something. Security guards in supermarkets often stop me for stupid reasons. And by often I mean almost every time I come to the store. Bus drivers, store clerks, sometimes even just random people on the street make snide remarks or verbally attack me when I talk to them. People avoid sitting with me in public transport at all cost, to the point when there's a bunch of people standing and nobody taking the seat next to me.
Basically, it's like every new person I meet doesn't even give me a chance. I'm trying not to let this affect my self-esteem, but I still can't help becoming a shut-in and being scared of approaching people or doing anything I might be criticized for. I still believe I don't deserve such treatment, at least not in such an amount, and sometimes I feel extremely bitter and hate people in general.