He hasn't gotten his tail caught in a door but he has taken a fall or two. He never seemed to have a horrible reaction but now I know even a short fall can cause major harm.
Has your vet checked for a vitamin A deficiency?
With the beginning of eye problems, kinked tail, loss of strength and unexplained weakness it sounds like he might have a Vitamin A deficiency.
Check out this thread https://www.chameleonforums.com/viatimin-deficiencies-cameleons-143583/
There is no check for vitamin A deficiency. It is diagnosed by response to treatment. I would not put vitamin A very high in this case. I would like to see blood work to evaluate liver and kidney function.