My FP is someone I met online 6 years ago.  For most of the time we've known each other(again only online), he was enamored with me.  He still is.  But he's accepted that we aren't going to be together in an real sense because I am not available romantically and I am not willing to meet him.   

He deserves his own life and happiness, I get that.   He's reached a point where he met someone a few months ago, online.   He was quite taken with her.  I flipped out, probably not surprisingly, and said some mean shit and disappeared for a month.   I did it for multiple reasons--for one, I felt abandoned/replaced.  But the more mature part of my mind knew that his relationship would do better if I wasn't around.  That month was pretty terrible, but I was doing okay.  

Then he reached out to me repeatedly one day and I broke down and started talking to him slowly.  Over the next week or two we talked it out and we are now talking regularly.  I am still pretty confused and have mixed feelings about it.

So his thing with the other girl is not working out well.  The girl is being flakey, delayed meeting him, is hanging out with other dudes--he's kinda upset.  She lives across the country--he met her on a video game, not like a local dating site).  

I am happy to have him back in my life, but I hate that he's upset about someone else.  I feel like the boring old background person.  I hate not being the important one.  I know--I can't say anything--I cannot and am not willing to be his romantic partner--of course he needs someone else, but I hate it.

When I feel particularly dramatic, I just want to blow it up again and disappear.  I like a timebomb.

How do I deal with this?