I agree with careya123, therapy is a must! My program we were required to be screened prior to surgery a d for you to go through this at a young age from psychological stand point, most 18 year olds don't have a lot of self- awareness.
I also experienced hunger early on into surgery,but with the support system I have we figured out I was not getting enough Protein causing my hunger. So I increased my protein/shakes, it helped and my life has changed immediately.
For solving your problem now, I would see a surgeon who is apart of an accredited program. They will know where to go from there. I know the program I am in is highly rated. Once discussing options I would then see a nutritionist who deals solely with Bariatric nutrition. They are the best suited to help.
I am so sorry you have not had the results hoped for, don't give up! Your life can still change. Feel free to message me if you ever need to talk or support.