The three week stall like others have said is very real and very common don’t beat yourself up just continue to stick with the nutrition guidelines and exercise and the weight loss will pick back up again. Wishing you all the best!
Have you contacted your insurance company or looked in your benefits guide? I have ChampVA and in my benefits guide there is information on revisional surgery that indicates if you are not within 10% of your goal weight.... however I am sure it is more to it than that lol. I remember reading a while ago that someone asked their doctor to perform an endoscopy or something to see the size of the stomach because the restriction was not existent after surgery.
Are you feeling restriction and just not losing or no restriction and not losing? If doctor isn’t willing to help I would seek a second opinion as well.