Several things you've said are definitely relate-able.

I feel so hurt and low all the time about my immediate family. I'm so tired of them putting me down and making me feel bad!
They have paid for both of my sisters college courses, I never received any help from them

I've always wanted to cut ties with my family but wasn't strong enough to do so. If they are having a major negative impact on your life than you should try to learn to set borders with them physically and emotionally.

((((((Hugs))))))