I'm sorry honey, but it sounds like he's very sick. There are quite a few things that cause circling (inner or middle ear infections, brain tumours, strokes etc) but none of them are good and coupled with the runtiness, lack of hair and abnormal development, it doesn't sound like he has a good prognosis. I don't want to upset you but, personally, I would euthanise him before he gets any bigger.
Sarah xxx
Sarah xxx