I think what part of it boils down to is you doing your best to look at your life objectively and then asking yourself - "How would I respond TO ME if I was my best friend?"
What would you suggest and offer in the way of advice?
My questions are: What happened in the past when you put the ball in his court and left it there?
What happens when he shuts down and you don't try to "open" him?
What happens when you sit with your sadness until you decide to get up to make a nice cup of tea?
What happens if you don't return his call?
What happens when you chose to do something nice for yourself and don't include him because you decide you don't want the drama?
I could ask more questions, but I'll leave it there for now.