Hi Norbert,
I'm sorry about your loss, I just can't imagine what it must be like to lose your best friend.
The feelings that existed between you and your best friend, I can relate a lot to!! I have a friend like that too. He understands me better that anyone else, and although I care about many people, I feel he's the one who's always closer in my heart than anyone else. At times I've had fear that my future love, will never give me the same emotional response as my best friend does. I love him to death and he was the only one I loved when I was in a really, really dark place and didn't care about anybody.. But he was my light in the darkness and I am so honorod to have him in my life. Right now we live very far away from each other and at times we didn't speak for months, but I always had him in my heart no matter what. When I thought of him it made me a better person. And right now where I can love myself and other people again, he is still a bright star.
I don't think you have lost your friend in the emotional kind of way. He will always be with you no matter what and I am sure you will meet again someday.
Don't be scared to let other people in so close. I think that this experience has a purpose.
They always do. We eventually figure out what the purpose is. Don't lose hope, grief has different stages, cry if you want to, cry if you need to, time will heal your wounds and you'll eventually come to terms with your grief.
All the best to you.