I've had gained 10 lbs since Feb 17 and also have LC. I have forced myself to walk in multiple increment of 10 minutes in the house. It's a struggle and began with walking 60 second and adding another minute every few days. I am up to 2 to 3 10 minute sets. I have an endocrinologist who prescribed meds to help with my thyroid function which was destroyed by covid. Perhaps u can get help from an endo.