Problems matching melody to chord progression

This is what happens:
I come up with a chord progression Im happy with.
Then I try coming up with a melody over it using a some notes from a major scale or a pentatonic scale in the key that I think fits the progression.

doesnt sound right.

I try to come up with a melody using the root notes from the chords, sounds mundane.

Even harder is when I come up with a melody then try to come up with a chord progression.

I read DHodge's melody article but still feel stuck, frustrated, confused
if anyone can help, Id really appreciate it. thanks