Wow, it is sure not looking good!
Did you try the scratch test? The "fuzzy things" on the branches would be buds for new leaves, but they should be green, if they were going to open up. There's a big area on the trunk where the bark got stripped off (was it in some kind of horrible accident?) and it's looking very dead and dry under that.
Still can't tell if it could have been sick when you got it, without knowing when you got it.
Another thing that you can check is to take it (gently) out of its pot and inspect the roots. If over watering was the problem and it went downhill that fast, it might well have root rot. So look at the roots. Brown/ black roots, mushy roots, rotten smelling roots got root rots. At that point your tree is trash. If the roots are white and firm and smell ok, then you still have a chance.