I can only imagine how you feel. I would not appreciate if my mother did that to me. However parents have different ways of raising there kids, tough love can be one of them. You seem to have an extremely good work ethic, maybe it's also because of your parents being strict with you ?
I have a friend and he was always spoiled by his parents. He doesn't have a job and hasn't had one for a while because his parents are always too nice to him and let him do what he wants.
However considering that you are now already a grown up and you have shown that you can take care of not only yourself but also your entire family I think you should tell your mum exactly how you feel. Considering the hard work you do you deserve to be treated respectfully and maybe some good communication can help to solve the problem .