Reconsidering after 6 mo diet

I am up 10lbs during my 6 mo supervised diet. The first 2 months I followed the diet and actually gained weight. After that I was just marking my time. The thing is I worked out iwth a personal training group and dropped 45ish lbs. I had maintained this weight up until this new diet. I know this sounds odd, but alot of it was fear of failure, which I did infact fail.

I am considering going back to the gym (it is a personal training group that also required you to follow a diet and read what you ate every day....6 days/week)

I started back at the gym last year but had just started a new job and was overly stressed (I had been fired from my last job and was over the top stressed). I have been at the new job 14 mo now and all is going well.

While I weigh 330 lbs and it is unrealistic that I would drop down to 200 I cant help but wonder if I gave the gym another shot I might lose a good number of pounds.

Even though my package has been submitted to the insurance company I cant have the surgery until November (work restrictions) and am wondering if this time might be best spent tryihg to lose weight the old fashion way again.