Rip the bomb of firstly, then put the bomb by the door and take shelter behind the bed, because I suppose the bomb wont destroy the whole room because he had to have a reason for putting the bomb on my forehead... and when it explodes I'll need a way out or else I will just starve and that's worse.
Then I'll find out where he lives, and then use some of my superglue to glue a bomb to his balls, and trust me, it dries fast, and yes I'm expecting him to rip it of, and it'll hurt, so much so he wont even notice the bomb on his forehead....