What Causes Weight Gain Post HCG?

I took 3 rounds of hcg a year and a half ago. I lost 25 lbs but I gained 10 back. I am having such a hard time losing weight now. Does hcg mess up one s metabolism? I do not want to do hcg anymore. It made me so paranoid about food and weight that I felt I was losing my mind. But my metabolism has significantly slowed down now, I m afraid I won t lose weight without it anymore. What should I do?