Penny

It sounds like you are doing everything right.

If he told you about the questioning...then, yes, stop it.
It sounds like he does still care for you...so I would be a
little more unavailable to him. Maybe miss a few of his calls.

Be mysterious, rushed to get off the phone without any reason
as to why...end the conversation early and be the one to end it.
Don't tell him everything you do...let him wonder.

Just hang in there...it does take time.