I can relate. For whatever reason, I have always had friends that are significantly older than me and I've been lucky to have had mentors during various periods of my life. I'm sorry to hear about your best friend-- that must be difficult. Everyone needs someone to confide in, but you're right that it's not always easy to do so.

Except for the past few years, I've always had one or two female friends who have been willing to listen. If you have some female friends that you trust and who you think might have good insight, you might try that. For one, it might help get around the awkwardness that a lot of Western guys feel about baring emotions and being vulnerable. With any friend, it might be worth framing the problem in a forthright way, as in, "hey, if you don't mind me getting serious for a minute, I have a problem that I need some help with that I'd really like your perspective on." That way, whoever is listening can shift gears. No one likes it when someone starts getting heavy out of the blue.