I'm sorry - that's all rather sad.
What comes over from your explanation is that although there was a huge attraction, neither of you was prepared to compromise on the way you lived so that your lives could dovetail.
It sounds as if he wasn't as committed to you as much as you wanted or hoped. I can see that being on tour ( maybe he's a perfomer/musician) would make the relationship tricky, but that in itself was not insummountable, nor is the age gap.
But I am still not sure if the split was 50/50 or more like 60/40 , 75/25 his choice. If he made the break, didn't come back, then you said you wanted him as a friend only, it sounds as if it was more his choice.
But on the other hand you told him it was over for good- so how did you expect him to behave? Most men get over relationships by getting into something new pretty quickly. Far more quickly than women.
Sadly, when a relationship ends it's not the sex that people miss most but the emotional closeness- when my ex fiance broke off our engagement it was my "best friend" I missed most- the daily chats about mundane stuff.
I think you are torturing yourself - friendship after love is very tricky and as I said in my first post, something that sometimes evolves a long while later.
You are being unrealistic to expect the same level of emotional closeness , and also his new partner might not be happy with that.
You arent' missing a friend - you are missing the man and the relationship. being good friends is fundamental to any relationship, and yes, you will miss it.