Help in studies for college

I am in need of a new PC because of my poor life, I have tried to fund my own PC. But due to lack of money. I have been in a bind. I am currently in first year college studying Computer Science that is why I need a new PC. I`m currently living with my aunt and grandmother. I am in a desperate matter due to the sacrifice needed for my younger sisters budget. I have also have one parent sustaining our daily needs. That is why I cant save up money I tried but always use for school purposes, and I am not allowed to have a part-time job because of family reasons.