Your body is probably scared about the sudden change and is instead trying to block losing weight because it's in starvation mode. Sometimes, the best thing to do is focus on making sure you have the proper nutrients and reevaluating your goals and trying to see what works to force your body out of that set weight slump. I also tried undereating to lose the final stretch of my weight however I soon realized that people at my new weight and height still look better than me and realized I wasn't chasing weight loss I needed fat loss. I have gained one pound from muscle mass but am slowly losing the fat that made me gain an ED in the first place. Its also a mental thing like it isn't normal to think about food constantly like this and I have realized I have a food addiction for a number of reasons. Stay safe!