I work for a sub contractor on his truck doing deliveries, im a helper i youst to make 150 a day with him,?

then i left him looking for another job, because that job i was puttin crazy hours like 16 - 18 hrs a day,also i have been having alot of back problems from this job which is the main reason i chose to quit, so when i didnt succeed in finding a new job, i went back to him, now hes giving me 100 dollars a day and doing the same work, he treats me like **** and has no respect for him self,because im now in need of work, is there anything or anyone i can complain too ? and there is no benefits or anything like that.