I always rejected him but he pursued me anyways and after i fell in love he said we just dont fit forget about it. Why?
He said he thinks we do not fit?

After he had time to get to know u he decided he didn't like it
Payback or maybe his mind changed the same way yours did.
Probably out of spite then for you rejecting him.
To get back at you but again I dont know as Im not there to see it with my own eyes.
Opinion
2Opinion
If he don't want you, he don't want you. Get over it.
He learned who you really are.
Superb Opinion