Sometimes, when people are afraid of others, they either take in characteristics that they ar4 afraid of into themselves or project them onto others. It sounds like you are afraid that in enclosed areas you might get touched or hurt, and that triggers the impulse to do it first. Or it could simply be that you are afraid that you will express your fear of people violently. I know it is hard to believe, but you can gain more control over your emotions and reactions, you've managed to already! It takes work, and it takes time.
when you talk to your P doc, maybe he can recommend someone to work with you. Maybe you can try by working CBT with someone. Many of these therapists can handle not delving too much into your past. It's all about dealing with what's happening now. I realize that it is hard to trust when you have been hurt, and I guess by more than your therapist. it's a hard long road, and II wish you the best. get help soon, and take very good care of yourself.