I think prioritising always helps - depends what it is you're stressed about, but if you've got lots of things you need to do, it can help to write it all down and put things in order of importance, work out how much time you've got to do them, and set a realistic time to get them done in.
Exercise is good for stopping you feeling stressed, which is also a good incentive for getting fitter and healthier, and getting a lot of sleep can help you deal better with things than being tired all the time.
If you're feeling yourself start to panick about it all, just stop whatever you're doing and rest, because you can't get anything done when you're too stressed about it.
But it definately helps to talk things through with someone, are you sure you haven't got anyone to talk to? Any friends, brothers/sisters, parents, family??