Udie,
Sorry to hear that you're hurting but that just means you are open enough to care about another person. You can make it through, it will take some time. Try to stay busy for a few days then take some time to reflect on what your buddy meant to you. Remember the good times and the bad as well. Firm it up in your memory to keep with you so you can "consult" him when you need to. He isn't all gone as long as you remember him and can learn from the experiance.
A final note about this. Use this experiance and time to realize what it is you have in that gift of life. It is always short, no matter what the years may have. Use the time as best you can. It isn't what they have done that most regret at the end, it's what they SHOULD and COULD have done that many regret. Don't let the one irreplaceable and non salvageable resource you have, time, go to waste. Use it, spend it but most of all LIVE IT as a life, not a spectator sport.
Thoughts and prayers,
Mav