Ok my phone is being a butthole....?

for the past few months my phone every week does stupid thing like froze up or one time it could work with only my charger plugged in and the battery out and another thing that creeps me out most is the music i download and it goes faster and sounds like a high pitched chip munk i dont know what to do should i get a new one or is there a better solution to my problem? plese help! thankss