I'm really sorry to hear that. The best thing you can do is be really supportive of everyone, especially his friends and relatives; this will be particularly hard for them. Don't try to keep to yourself about it; everyone will be feeling the same way, and although it's difficult you will probably feel better by sharing your feelings.
Remember what a wonderful person he was. By all means, miss him. But do move on with your life, and try your best to 'get over' this tragedy.
You can always call Childline or the Samaritans (the latter irrespective of your age), and don't hesitate to see a counsellor if you think that will help.
Again, I'm really sorry.