Question - how would you feel about doing Seller Financing? If you have a 10% Downpayment, and a good explanation, as well, as being able to show that you've paid everything else (mostly) on time for the past couple of years, you probably could get a nice home, with a 5-6% Interest Rate on good terms.
Than... you could walk away from this home, rent it out, and let the first foreclose. Whenever the waiting period expires, you could than Refinance the new home (potentially in your significant others name only) into a New 30yr Fixed Rate - with a lower interest rate, and get a lower payment. That might be your golden ticket.
The other possibility I would consider - is finding a cosigner (like a parent) or someone who would do you the favor, and getting a loan only in your significant others name plus the cosigner. There are a lot of 3% - 3.5% down loan programs, with PMI -- that would let you buy something new. Once again, as soon as you get into the new home, you could walk away from the old, rent it out, and let the first foreclose.
I think both are far better options -- than draining your Future.