His moods go from the kid I used to know which I have only seen twice to this hyped person I dont reconize. = sounds like he is " growing up". people do change...

changing subjects constently = high

and is parinoid about things = not rare at all!

and obsessed with making money = maybe just maybe he wants to buy more weed?

He says when he was normal he is trying to wein off himself and if it doesnt work is going into rehab. = maybe he gets a little too weed happy?

Problem is when hes hyped up he wants nothing to do with this idea. = who wants to go to rehab for weed when they are high?

What can I do to help? = teach him moderation, or punch him in the face every time he smokes, maybe he wont want to smoke anymore from the punching. Good luck!