Seamus is completely right. Time heals nothing. What you have to do is to let go. In this life we meet some wonderful people, but in the end death separates us all. It feels terrible to loose an important person, but reasons why that kind of experience can turn your life in to a bad direction, are the wrong reasons.
We cant own people. And death if anything slams that fact in to our faces. Do you think your friend would be happy to see you miserable and wailing in your sorrow, while loosing touch in your own life?
His death cant destroy your life by itself. It is your own choice whether to make your own life bad and blame it to his death. What you need to do is to let him go and live on your life. Which i think your friend would wish you to do so also. Nothing can take away all the good memories of the things you shared with your friend, but the fact is that he is not with us anymore and you have to go on in your life in pursuit of more happy memories for the future.