What is wrong with my slow computer?

I have a basically new laptop which was purchased about six months ago. About a week ago, it began getting slow about 5-10 minutes after I turned it on. I've ran avast, malwarebytes and I've defragged my computer many times, but it's still slow. It starts getting especially slower when I play music. The music starts to get really choppy and typing is delayed. This little machine is my baby, help!!