I don't know how to prioritize?

I'm failing school because of it. Is it the possessions i have? Watching tv all day, always facebook and youtube. I cant even get my school work finished. How could i set my priorities straight? I'm scarred I'm ruining my life like this. I never finish my homework and i want to. Something clicks in my head and says ''screw it, i wanna watch tv'' or something like that. I hate it but i cant help it. Am i sick?