why are the voices in my head so loud

Every time I do something, it seems like there are voices in my head. There's one who tries cheering me up, but the rest are screaming about how I suck, and how terrible I am, & how I can never do anything right. I wish they weren't there. When I listen to music or do something I enjoy, the bad ones go away, but when I'm doing anything else they are there :[