it may or may not help, but I used to be convinced I wouldn't live past age 25. You practically quoted my younger self.

Sticking with the therapy can be a huge huge relief, maybe not right away but you will know it when it happens. You may find yourself surprised at feeling overwhelmingly loved, therapy and in real life.

Being with your toxic family is tainting how you feel about yourself. All you can do in the short term is try to mentally wall off their bs.