If it sounds good it is good. With those three chords alone there are plenty of notes to make up a melody. Lead the listener to the next chord.

Have you ever considered auditioning Gary Burton’s jazz improvisation class thrrough Berklee online? It kicked my butt. However, the comment about leading the ear of the listener to the next chord was one of the only concepts I recall from the class that gets one away from the memorization of scales.

Victor Wooten says something like ‘you are never more than a half step away from the right note’.