21 year old stressed and need advice URGENT?

I’m 21 years old in college last week for my A.A.S and I’m working about 20 hours a week while taking 17 credit hours. I make around $400.00 per month and I’m trying to help my sister pay bills and also save for a car. I’m really stressed now because I feel I have no opportunity My mother is stressing me out I don’t have enough money to move out because I have to help take care of other people and only have around $ 30.00 left each month . I have a 3.7 *** G.P.A and plan on joining the military after I get my B.A. I come from a poor family and I have no support at home my mother doesn’t care and my sister is all about boys. I know I’m 21 but I have no one to encourage me to continue my education. At times I feel my family can’t understand me I go to Baker College and will be finish with my A.A.S after my internship. I want to continue to my B.A but really don’t have the strength to finish because the lack of support I have at home. I currently work in retail as a temp job but I really want a salary job someday and live a great life. Now I live in hell and feel that I’m stuck here and just can’t see myself every getting out of this environment every time I take 3 steps I fall down 4. Have anyone else had the same problem I’m having and any advice?