I am so, so sorry to hear this. It makes my heart hurt.
I've been through this twice, with exes (7 years each) whom I loved incredibly and whom, once I no longer cared whom they were sleeping with, became my closest and best friends. The second one, who had moved away cross-country, came back to live with me and I took care of him for two years until he died.
There are people who won't understand that just because you're no longer together you hurt quite as much as though you were. This is something you need to understand for yourself and not, necessarily, to look outward for validation. I've always been of the mind that once I love someone it never stops; it changes, of course, and I move on. But I've never stopped loving anyone I've ever loved. I wasn't in love with them, but well...
I know you're hurting and I respect you all the more for it. It speaks volumes not only about your relationship with this man but about whom you are as a person. Give in to it; let it go. It's all good.
My heart goes out to you.
