A couple thoughts. I totally get the lonliness and do not at all discount what the others have suggested. However, I'm GREAT at being alone - perhaps too good at it. I very much enjoy alone time and always have. I also really enjoy steak, pizza and ice cream - but not every day! You've had a long run of it and I think that could be part of why you are growing more lonely. You need some adult time with other people. Even a few practice dates might be a god idea. I know, I know, you're not getting asked out - I get it. Not a lot of good answers from me but I totally understand. Hope that helps some.
As for the grieving, I don't think you are grieving the actual R at all. It's what you hoped it might be (but clearly wasn't) and what you are hoping for that you want, miss and grieve. That guy was not it. He really wasn't as you are seeing now. But you and I really would like it to happen and that's what you/we miss. It's just a matter of time and someone will come along - I really believe that for you - even though I only half believe it for me. Once again I do get it. Hang in there.
We cross posted, Don. And I have to say, you articulated how I feel and my mindset much more succinctly that I can. That is EXACTLY what is going on with me. I am pretty darned good at being alone. My friend's have actually have expressed envy over my abilities of being able to be alone. It's just not something I want every day.
You even pretty much nailed down the exNG thing. I sure did love him. I loved who I thought he was and who I thought he could be. But the R, I don't grieve that. It was very one sided he was so wishy washy. Just what I thought we could have had. I still sit in the hurt of choosing this other woman 5 seconds later to give to but not me. It was reopening a scar my ex left behind.