You obviously put a lot of time + work in to making his set up, so it's easy to see that you care for the little guy.
However, the tank needs major changes and so do the lights. And your guy is waaaay too small to brumate. Your uvb is a coil or compact [ the 2 prongs ] so it's not putting out very much at all, and only in a very small area. The companies make big money on a product that is not adequate for it's intended use. He will never get better one bit in that set up, he will get worse. It's imperative to do some changes very quickly. Order a new
uvb bulb ASAP, you need a long tube [ linear ] Reptisun 10.0 . He also needs to be in a smaller tank and no rocks like you have there. His bones are brittle now and could actually break trying to walk over those. See how his front arm curls in ? That's bone disease. So set him up on folded up newspaper and just put a sheet of non adhesive shelf liner [ Walmart or Dollar store, etc ] so he isn't on such hard surfaces.
You need to section off half of the tank as well. Set up the flooring like I mentioned and get the proper uvb lights. He is sleepy now, not because of brumation, but because he is not well and has no energy. Make the changes ASAP and hopefully you'll see him do better but it will take a wile. When you feed him, make sure he stays in the heat of his tank to digest food, he can't be out for hours with no heat or uvb. I know you want to snuggle with the little guy but he needs to be where the heat + uvb are. Keep in mind that without these changes he will never get better.