losing too much weight before surgery

Got reply from bariatric center today and after seeing my regular doctor yesterday like they asked got it documented that my BMI is now 35 again and what I did to gain it. They sent the report to the Bariatric clinic. I finally called then this afternoon and was told. Didnt matter what my BMI is now when they saw the surgeon it was 33.8 and that is what was reported in my chart so as far as insurance is concern I no longer quailfy.  So no surgery they said to wait at least 3 months and try it again. But with my gastroparesis I wont be able to gain ior maintain where I'm I know I will be a lot less under 35 BMI by then because of how sick i'm of from the GP.  They said maybe could get it approve for medical reasons but that is really hard to do.  Or I can self pay. Stuck between a rock and a hard place. I've even consider going to Mexico to have it done, but I afraid with my GP problems. What happens if you need follow up?
Tonya