Surgery without insurance

About 4 years ago my doctor suggested bariatric surgery but my insurance excluded it.  I have been dieting all my life and slowly losing that battle.    I put the surgery off because I thought Medicare would pay for it and I only had 3 years to wait.   As it turns out as long as my primary insurance excludes the procedure Medicare also excludes it so I have to pay for it myself and I really don't know where that money is going to come from.  I have high blood pressure and arthritis in my knees that losing weight would help and now I am pre-diabetic.  The doctor says do it now before I actually become diabetic.  The surgery is scheduled for Feb 18, 2019.  My husband had to retire early 4 years ago for health reasons and we have downsized and economized quite a bit.  We are currently living paycheck to paycheck and I don't believe I can ever retire.  If I can get this surgery and lose the weight I will be able to be more active, work longer and care for my husband.  Any help is greatly appreciated.