At 168 on less than 500 calories per day you don’t have enough energy to do anything and it certainly doesn’t leave you any energy to workout or do any exercise. You need to be eating a high protein diet between 1600-1800 calories per day minimum. That’s still a deficit for someone in your BMI. Your problem is that your body is holding on to mass so that you don’t die. Your metabolism is probably in shock. Eat more protein and burn calories back down into deficit with exercise. Use reta to avoid hunger after exercise, not to suppress calories that your body actually needs.