What can I do legally about my parents actions?

I am 31 and have been living at my parents. They have given me an allowance of 120 a week and I would do vacum and dish washers. Now they said to they cant affor dit no more and aint going to pay me. I have been a god person and still did it for past 3 months and they havent given me more than 40 dollars. Cna I sue them for a agreement? They know that I have been actively looking for a job for 8 years. I lost my job because I parents didnt let me use their car.