Why am i seriously scared of being sent to a mental hospital?

I know I have mental issues; namely depression, anxiety, mood swings (from depressed to manic), cutting myself, and hurting my little brother (not badly, and usually as a way to punish him for being annoying, plus it just feels good for some reason), and I've been getting help, but im really struggling sometimes, its like I have horrible depressed spells, and when im not depressed I have mood swings and I feel like im losing my mind, and the longer I go without cutting the more I want to, and the only 2 things that seem to make me feel good are hurting myself and hurting my little brother.