When you say that the therapy options wouldn't be suitable for you what do you mean? Sometimes you have to do the basic options first, one because some of the skills would be useful later on and secondly because it can help identify what might or might not help.
Do you think you could talk to your parents about how things are when they get particularly bad? I think we are all wary about showing our worst but they may well be able to help and it might help them understand what you are going through. Do you think you could find your family some information relevant to what you struggle with so that they get a better idea of what you are contending with.
Alternatively, if you are sure you are never going to change their mind, do you think you could come up with a little mantra for when they do say this things to counter their opinions.