[Bobber]

Fold 5th. You will still have almost 5 big bets, which is critically short, but just enough to make a comeback with. Now you are just chasing very few outs - hearts are semi-dead after 4th and one of your kings is gone - and that is hoping that Seat 5 hasn't already filled up. It's very likely that he started with a small pair in the hole.

3rd and 4th street are fine.