Morally they should repay you the deposit plus a pro rata share of any increase in value since they bought the house, but unfortunately you can do nothing. The hardest thing will be to let it go, on top of the sadness of the break up of the relationship. Perhaps the partner thinks they are owed the money as compensation for a wasted 10 years!
However, although you are morally right, the only way to get over it and not let it eat away at you and make you bitter and ill, is to put it down to being a mistake to learn from. If you can bring youself to politely tell the partner how you feel, good for you. PS Your husband sounds loke a saint!