I don't understand the dynamics. But as the house is owned equally, the individual contributing more to the household really is in the position of making and dictating the rules.

It seems though they are doing so with litte respect for you. I agree with comments above suggesting you take some control of your own concerns and needs by moving into a more independant situation. There is help you are likely entitled to. So too should you seek some legal advise about having your son buy you out of your share of the home and assets. This is no different that the situation of couples divorcing.