I can't be certain, since I have not seen your program or your progress, but it sounds like you need more than just protein in your diet. I would be interested to know how long you have been eating protein only. A true Keto diet requires a good deal of fat, in order for your body to learn to use fat as fuel. This sounds more like starvation to me. In which case, your body will do everything it can to hold onto fat reserves and break down muscle. The key with dieting is to eat as much as you possibly can, while still losing fat. Sometimes, a person may have to go all the way down to a diet of just protein and veggies, but this should only be for a short time, at the end of the diet, if needed. I believe that more food would correct this issue. You can't eat protein only from now to OCT and expect to maintain size while losing fat.
Sorry for the delay in reply. I understand this was more of a time sensitive question, but the QA had be down due to technical issues and I am doing the best I can to catch up. I hope this info still helps you