Getting Out from a Joint Loan

Hello,

I bought a house with my ex when we agreed to get marry but then he called off our engagement. I want to get out from the House entirely. Getting out from the ownership and of course the loan. The house is still under development and will be completed in 2015.

He told me that there's nothing we can do until the key have been handed to us because the developer will not entertain our issue. Which is fine but I have few questions:

1) Could I do anything right now to get out ?

2) If it is true that we have to wait until the house is completed, what can I do to prepare myself to get out?

3) What would be the correct process in paying all my debts for the house?. Do we re-finance the house or he can just buy off my share of the house?

Please help. I just want to remove this problem once and for all.

Thank you