Is it normal that i just can't care about anything?

I dropped out of college a few years ago, after spending over a month lying in bed because there didn't seem to be any point in getting up and going in, i just couldn't give a damn about any of it.
I was living at home at the time.
I moved out and it all got a bit better, for a year a lived away - about as far away as you can get - and was happy, i was working and planning on going back to college, that summer, near where i was living. But my funding for college fell through and I'd already quite my job. Oh well.
I moved back home, started college there again - thinking it'd be different now.
It went great for the first few months - top five of the class easily, the work is a piece of piss to do and never took very long.
I think it's been growing for a few months but i only just realised it a few days ago, I've stopped caring, I'm tired of being happy and trying to act happy with my friends - I just want them to go away and shut up for once.
College doesn't matter anymore, I'm finding it hard to get up in the morning again, the only reason i am is because of the work placement i have and the fact that it relies on me still being in college.
I've stopped caring how i look, whether I'm taking part, if my school work gets done. It takes so much out of me to smile or laugh when i know i should.
It's not even that i want to give up, it's jsut that i don't even give a damn.

Is this normal or is there something wrong?