weird behavior

I have a seal point himalyan. He is 5 years old and he is a weird little fellow. He has lately become scared of shoes whether they are on feet or on the floor. I had to take him off cat nip a couple of years ago. He became addicted to it. It was like a drug to him.
He hasn't been the same since. Should i leave him off of it or give him some more? He hasn't been really happy since I quit giving it to him. When he was on it he would sneak around like something was after him or maybe he was seeing things.