Sorry you have to deal with such intolerance. I also did pretty good with school except for math but I have simular sorts of issues...I get easily confused by changes of plans and can be slow to understand it.

Also if your parents are telling you to kill yourself that is abusive, I don't want to stress you out too much but you may need help with that situation because it can't be healthy might be worth talking to someone like if theres a counseler at school...being in a situation like that certainly does not help mental health.

As for now try not to beat yourself up over this, you're not pathetic and useless just because you have some mental difficulties...that's just crap these toxic people have beat into your head but try not to believe it.