I agree with the previous poster to have some mental health help will be very beneficial after surgery to keep what you're talking about in check.
My surgeon and nutritionist talk extensively about patients that replace food addictions/food control issues with other addictions/issues after surgery (drinking too much, being too restrictive with food, over exercising; etc.) so I've been very aware of it. Not saying that will happen with you, of course, but some extra support might help you feel better.
My mother is an alcoholic and I've been worried about becoming one my whole life, so I understand where you're coming from.
Also - in my opinion, you'd want to make sure that you aren't disappointed with the results you're getting from all the HARD work you're doing and the changes you'll be making come surgery time. You're doing awesome, and you should feel proud of that already! It would be terrible to lose a ton of weight and be so much healthier, but then not feel like you've accomplished much because you were too hard on yourself.
Best of luck in your journey!!