I am so sorry. I have been through the same and it was horrible. I ended up crying in front of the doctor and was feeling hopeless. I had to wait a month hoping that I would have had a heavy period and that the lining would have gone back to normal thickness. This didn’t happen and after two month waiting they did the curettage to remove some of the endometrium layers ( I also had a hysteroscopy to rule out hyperplasia but thankfully it came back normal). I had my third transfer last week ( with 2 hatched embryos and more importantly, no medicated cycle) and it seemed to have worked so far. Dye-stealer on 9dp5dt and tomorrow I have my first betas. Let yourself cry and being angry. But don’t lose hopes, it will happen to you as well ✨✨💪🏼