I need advice on parenting and how to cope with the stress of helping my pregnant girlfriend?

I'm a 17 year old student, and I'm currently balancing school and work in an already busy schedule...my parents are trying their best to help me with this all but its just not enough. I can't handle it anymore...I'm constantly being verbally abused by my girlfriend's brother and ex at school and on top of that working with my dad for long hours at night isn't helping me with getting enough sleep for shool and whatever. I'm only trying my best to help support my young family and unborn son but I feel like I'm failing them....on top of that my girlfriend is having problems with our baby because of her small frame and I worry about her more and more each day...she can barely eat anything in the mornings and sometimes during the day and she can't even stand for long periods of time without getting dizzy or sore. Can someone help me and guide me to do the right thing because my parents aren't doing a good job....