I had a friend who I was close to and had a similar experience as you did. I went on vacation without telling her, and she got mad. We didn't talk after that for three years. She passed away last March. We never reconciled. I attended her memorial dinner. It was a sad event obviously, but I am glad I attended.
I wish things turned out differently, but I did not do anything inappropriate. Neither did you. Try and reach out via an email, inviting him for coffee. If he doesn't respond, then that's on HIM--not YOU!
Sometimes the best lesson I learned with friendships is that not all friendships are meant to last forever. Sometimes friends come for a a specific reason in our lives. This buddy may have been here for you for strength and support. But you are stronger now. You have grown within your life. So whatever happens . . . you will move forward in your life with or without this person.
I miss my friend, but I am proud to have had the experience of having her as a friend for a certain amount of time. So think of the good times and not the final outcome-whatever it may be.