FRUSTRATED BY FAMILY DEMANDS

Hi RTers, my name is Jacob, a 32 year old computer scientist, i live in Benin city with my family (my mother and step father) and own a small Business center which has been sustaining me financially. I was born out of wedlock and raised by my mother. She's practically did everything for me with the little trade she did because my step father wasn't so interested in issues that concerned me. He never gave me money one day for my fees or up keep, it was all my mom and the little efforts i put in to raise money. I never really met my own dad, i just heard stories of him and heard he relocated from the country many years ago. 

Anyways, i managed and struggled to finish school and with the little money i saved up, opened the business center which is all i have presently. 

I have 4 other siblings all in secondary school. My step dad was a teacher in private school but lost his job 4 years ago. Since then, all expenses have been practically shouldered by me; from feeding, to paying of the children school fees, to clothing, to rent etc. My mom's trade hasn't been doing so well and my step father isn't doing anything reasonable. 

Right now it's just like i'm in a prison because i haven't really lived my life the way i'd have love to because of the financial burden. My girlfriend of 4 years has been waiting on my to be settled financially but with the look of things i really don't know when that will be. The demands are really so much. I dont know if i should move out of the house to start my life by myself or continue with this trend till God knows when. The annoying part is that my step father doesn't even appreciate what i do, he feels it's my right to bear the responsibilities forgetting he never really contributed to my training. 

Dear RTers, please I need your advice because i'm getting really frustrated.