[TheDeKay]

1. As others have stated, I don't like the 3bet as well.
2. But I think your postflop line is fine. He either has some weak Jx hand (QJ, JT), 98 or air. He might just double barrel here most of the time since our line looks weak to him (check this board twice = we can't have a good hand) and he is unlikely to have a very strong hand since his line looks pretty weak. Or do you have a read like "he does not protect good hands"?