Everything makes sense now.... little Phoenix is heavily infested with worms!
So he was limping and staggering around because he was weak with malnutrition, hence also the very dry and flaky skin (he shakes and it's like a snow storm).
He was wormed first with garlic then yesterday with Piperazine, hopefully he will finally be on the mend now.
He's been in the house for over a week, getting lots of rest, warmth, TLC and proper food (chick crumbles, scrambled eggs with olive oil and cottage cheese, poly-vi-sol, etc).
Yep, I'm an idiot for not even suspecting a parasite infestation and for not treating him weeks ago.
I didn't even recognize all the signs.
I tell you, this learning experience is a hard one.