"The house and rent/mortgage deal was supposed to revert to my being on the house deeds and him taking his off but he has changed his mind since I got married."
I'm amazed that a man would promise that to a new gf of just six months, but you are right to be annoyed that he has not stuck to his promise.
Certainly, I would stop paying the rent on that property now.
But I think you should also consider how you have actually done quite well here. You came into the marriage with no assets at all, and without even the means to adequately house your disabled dd.
After just six months, he bought a house for you to live in with your dd, to your specifications and to suit your requirements. He charged you rent to cover his mortgage and repairs/renovations, as all landlords do, and presumably this rent compared favourably with what you were previously paying on an unsuitable property?
Your adult dc now live in that house, and you live with your dp, being asked only to contribute towards bills and food.
On his death, you have a house for life.
To me, you are in a significantly better position than you were before.