I don’t think it’s weird, but your whole situation is pretty unusual, so I wouldn’t let “weird” become an obstacle for you. Some things are going to be weird no matter what you do, so just roll with it. You’ve said you and your brother have a good relationship, so why not just explain to him what’s going on with you and ask if he could include you at least sometimes? Not too much to lose by talking about it.

It sounds like a lot for you to deal with. I hope you’re doing better now and can find your way back to a life you feel satisfied with.