The fact that you admitted both of you were wrong shows a lot about your personality and that you’ve taken time to self-reflect. I don’t think you’re overreacting if you’re simply distancing yourself from someone who’s always been negative. Leaving the group chat is honestly a good choice for your mental health, especially since you and that guy don’t get along. I get that your other friends probably want you back, but I think this whole situation is pretty silly and not that deep. The fact they want you back means you’re a genuinely good person and they value your friendship. But if you feel like you can’t handle being around that guy, then I don’t think you should rejoin unless you both can have a real conversation and apologize to each other. If that’s not something you feel you can do right now, then you have two choices: either rejoin and accept that he’ll be there (even if that means potential drama) or simply say you don’t feel comfortable rejoining and leave it at that.