Gaining weight on protocol

I have been intermittent fasting and following a protein/veggie, 1 fruit a day, and occasional greek yogurt protocol with 2 meals, stopping eating at 8 pm and popcorn and coke on Fridays for joy eat. I lost 60 pounds in 1 year, maintained for 10 months, and in October 2018 I gained 5 pounds overnight. I have since gained a total of 20 pounds without changing my eating. I’m puzzled and coming close to panic. What should I do? My clothes are starting not to fit. I’m battling my thoughts “Screw this. If I’m going to gain weight anyway, I’m going to eat everything.” I do thought models and get coached on the weight gain regularly and can’t find a thought to get me through this without giving up. I had my A1c and glucose, thyroid and adrenal cortisol checked and everything in normal range. I’m out of ideas. HELP!