Satan's a pretty powerful guy, isn't he? Planting things like that in our dreams and our lives... Pray the Holy spirit to cover you, pray the Blood of Jesus to cleanse and heal you, then you look that old serpent in the eye and tell him 'it doesn't matter how much stronger you are than me, I belong to the one who is stronger than you, and in that I am safe from your barbs'. Then, calling upon the authority Jesus has over them, bind, silence, and get rid of any 'henchmen' that may have been in on the plan.
Reading a little scripture might help too, change the vision in your head from the dream to one of Gods word.
I'll pray for you too.