You have to go in to the Safari Zone and get the gold teeth or whatever they are called. While you are in the Safari Zone you might as well go to the secret house in the end and get surf, then exit the Safari Zone. Then you have to talk to the Warden in Fushia City (his house is to the right of the Pokemon center) and he will give you strength.
Unfortunately going back and getting the HM is the only thing you can do.
I remember that happening to me :/