Bulldog being scared

Question
I am concerned about our 4 month old Eng Bulldog.  He has been great until early today my wife made a loud sound doing house work and my puppy was so startled that he ran away and up the stairs.  Since that happened he has been walking with caution and doesn't seem to listen to what we say, won't get out of his bed to eat, drink, go to the bathroom.  He seems to be breathing a little faster and wanders outside to places he has never walked before today.  I am hoping this will wear off but maybe you can help me understand him and not have to waste a trip to the vet.  Thank you.

Answer
He got really scared that's for sure. He has no self-confidence at all. In the short term, you need to be patient with him and coax him to do the things he was doing before this happened.

Secondarily, you need to get him out of the house to socialize him.  Obedience classes are great just for the exposure. He needs to "desensitize".  Unless he has a chance to experience things, he will always be fearful.