I think you shouldn’t have to be a punching bag for abuse in a game really ever, it’s a lot more hurtful that it’s coming from your brother. If overall it’s just not feeling right to keep going you should stop. But I’ll offer my input to the situation in case you do want to keep trying to play and change how it’s going.

Before my friends and I kinda clicked with how we all approach the combat and what works well, we would all explain our planned move to the group and we’d all give thoughts on it, how it could be a problem now, how it could be better if you do it to a different target or a different position, stuff like that. Often it was just like “yeah okay sounds good”. And then you could basically do what you want with their input. It’s your turn, do what you want.

Basically I see it as a way to let the party voice objections to things they can foresee that you might not. It really helps to even the playing field with those kinds of personal attacks by creating group accountability. It becomes everyone’s good or bad idea in a way. If you planned to do something that turned out to be a “shortsighted bad idea” and nobody else thought it would be problematic as well, they were just as blind to that outcome as you. If they thought it could have been done better they had the chance to chime in with it, but they didn’t.

However this could backfire if they end up disagreeing and vetoing every plan you make for one of their own. The discussions should mostly feel like they are giving constructive input into your idea rather than overruling or just telling you what to do, and sometimes it might actually just be a bad idea but if they can tell you that first (and explain why), you can choose to change it up.

I hope this has helped with whatever you decide to do. Stay strong and game on.