I have been in you shoes.
My highest starting weight was 255. I am 5feet 7, so that put me around a 40BMI. On the 9 month pre-op plan I lost 55lbs. My family REALLY tried to discourage me from surgery saying that my weight loss was evidence I could do it myself.
The thing is, I have lost weight before, many, many, many times. I have said b4 that I was a great dieter, sucky maintainer, and super regainer (plus more). I knew I had to do something different this time, or I would just end up repeating my old patterns. (Remember that saying about Insanity: doing the same thing over & over and expecting a different outcome).
Upon much reflection / prayer/ counseling, I decided to think of the pre-op weight loss as part of my recovery & beginning of a new life. I had surgery at 198, at a 33 BMI. Many (family included) would call me a crazy person for having WLS at that BMI. But, I know myself and know my history. I have since come to terms with the fact that WLS was simply a last chance scenario for me.
My point is only you know you. I'm certain in time you will make the best choice for you.