An adjustment won't help you make healthy choices. If you can eat 1/2 a sandwich and be full, i don't know if you need a fill. That sounds about right to me. You need to get back in the game. You know what to eat, it's so darn hard at times. I know it is, but you can do it. You have to want to do it, and it sounds like you do. Start fresh, like you just had the band and get back to thinking and eating like you did when you lost that 30 pounds. It's hard, but it is do-able. You did it once. The right choices are a very very big part of this process.
Going back in for a check up / fill may still be a good idea. Get in and talk to them, they are there to help and want you to succeed.
Don't be ashamed. We all struggle.
VERY Best of luck to you!
You can do it!!!