Hey Man, don't freak out!
You are going to be ok, THC the substance in marijuana that messes you up takes about 30 days to get out of your system. However you should feel much better, anytime soon. Drink a lot of water that can also help to flush out your system. Good Luck

i agree with the drinking a lot of water i have heard as well that it takes quite a while for it to leave your system, and all marijuana is different, depending on the type that it is hang in there, you'll feel better in no time. maybe it's your body telling you that it doesn't want it

Its been said but I just was to reiterate, work out and drink lots of water!!!!!

The two posts above me are totally correct, weed takes a long time to leave the body.

Hang in there!

First of all your high only lasted probably 2-4 hours at the most especially if you only smoked a small amount.

Anything you feel after that is all in your head. You feel exactly like you did before you smoked, but smoking opened up a new perception for you and you are not familiar with it so it freaks you out. This is called plain old paranoia, it happens to almost everyone that smokes at some point or another. You probably smoked some really really really high quality stuff if your friend grew it. Usually when people grow its 400-500% better than the crap you can buy on the street.

You will hear how THC stays stored in your fat cells for days after you smoke- but this has absolutely NOTHING to do with the way you are feeling. The great and scary thing about good cannabis is the affect it can have on your imagination.... Its ALL in your head.