As I see it....
If you can find somebody willing to buy out your interest, you can sell your interest. If you do that, I would not expect to get anything close to 50% of market value of the home.
You can hire a lawyer and sue for partition and sale. That will probably cost $10-20,000, and may take a very long time to resolve.
You can try to convince your co-owner to let you buy out your co-owner's interest.
You can convince your co-owner to buy out your interest.

