You have AA, the best hand preflop. I do not understand why you are so scared.

I don't agree with your preflop limp. It looks as if you want to slowplay. Slow play is very bad with AA. I would raise 4.5bb - 5bb with AA Preflop, and if he calls, you know he has something something decent. Decent may include high connectors, suited connectors, or mid-high pair. The flop is not that bad. The downfall in this situation is that you have no position on him. But still, the flop should not scare you so much.