I'll start with some background story.

Back in high school i was bullied by other kids, even girls... I wasn't really social and never 'fit in'. At the end of 7th grade younger kid, punched me many times till i was bleeding, just to prove a point to his friends. I should've defended myself, but i couldn't. It crushed my already crushed self-confidence. I went to home-schooling, so i never have the same stress and social pressure. For 4 years i barely had any social contacts.

I try not to look back, but it keeps on bothering me even now in some social situations.

During the summers I'm going to my village and i made some friends there. But i often ended up in situations when they try to tease me(maybe they don't even mean it as offense, but just enough to lower my social status/value). I easily get insulted(i take it as disrespect) and my brain is freezing for a moment, can't think of any responses to shut them up or even if i do they keep on responding and sometimes it turns into a huge "joking" game, which I'm not any good at and it feels like I'm back in school again. However this happens in group of people, it rarely occurs when we are 1on1.

I'd love to hear some responses and even criticism on how to handle this kind of situations properly, because it even keeps me back from joining in gym, i feel like other people will mock me.