facebook spam/ads help!?

[Silloc]

ok so a friend of mine got fooled by an add and thought you could get a dislike button by downloading a certain link, so she put it on her fb account,i clicked the link to try it(yes i know its stupid) now my account is possed by the evil spam and ad demons and i have no idea what to do. whenever im on it plays video ads when im listeining to music and pops up ads in front of my chat boards, so im really pissed of right now, could you help me please, if you can thanks.
already changed my password,it didnt solve the problem.