Why do i not feel like doing anything anymore?

I'm 14 and i domt feel like doing anything anymore i used too love drawing, working on my bros car with him, watching F1 with my dad, walking, playing cod and minecraft and other stuff but for the past like 4 or 5 months i don't feel like doing that anymlre any of it i just tried drawing again and i just thought nah i can't be bothered so i didn't and the last time i drew was the 19/3/14 (i mark my drawings with the date) and that was a car and i tried drawing one again now but i couldnt just couldnt the only things i can be bothered doin is lisenin too music and reading (sometimes but rarely) when i walk i think its a chkre and get very bored my friend says i'm depressed but i'm not sure i'm sad and down about my looks and not having friends and sruff but i don't know
Why am i feeling like this