How can I walk away?

I'm 32 weeks pregnant with my first baby and right now I feel like I'm under a lot off stress with my parents. My father has a drug addiction and I'm very worried about what could happen because he's diabetic also and is constantly sick now. He was just released from hospital about a week or 2 ago and now he is sick again. My mother is so self centred, addicted to prescription drugs and possibly Street drugs also but phoned me up with every little problem she has. This topic sounds silly but there's so much going on with them atm I just don't know what to do, but I know for sure that I don't want this in my child's life but for some reason I just can't walk away from them:( I just need to vent! Sorry