Take it one step at a time. Meet with the new surgeon. Ask lots of questions. If he says no, find out what it would take to turn it into a yes. How much weight would you have to lose, etc. Different insurances and even hospitals have requirements of their own but a good surgeons office is used to working with that. In my case, first I had to lose 40 pounds (not easy when you can barely walk) the insurance turned me down once( Surgeons insurance staff did a good job of sending more paperwork and i was eventually approved), then finally we couldn't coordinate the surgeon with hospitals approved by insurance and i had to pick a different surgeon.
It sounds overwhelming but it all worked out fine in the end. I'm nearly 9 months out from my new knee and haven't been this active in years. Everything is good. It's worth the effort and even if i did have a setback or two, persistence was worth it. I am no longer in pain, i can walk for hours and i have my life back. I hope the same happens for you. Dont give up!