I say call their bluff.

Your parents say they'll cut you off if you don't act a part of the family. Do what you want and see what happens. The threat of turning off the financial spigot is their last means of control. If they actually turn it off, they have no way to control you any longer.

I suspect they won't actually do it. And if they did, you'd at last be free because you'd have nothing left to lose.

Seriously though? I doubt they'd kick you out onto the street if they are as concerned with appearances as you say that they are.

In other words, do what you want and ignore them. It seems to be the natural conclusion of the relationship.

If your dream about your dad is a memory of an actual event that happened, then your dad knows full well the real culprit behind your mental and emotional issues. They probably both do.

Finally, would they really render you homeless while your brother is watching? It doesn't seem all that plausible and you hold power because an accusation of abuse could risk having their son removed. You have more power than is readily apparent.

They may not be nice or kind or loving parents, but they don't strike me as idiots. If I were a gambling man, I'd put all my chips on the card that says that they're not going to cut you off.