There seems to be a bit of an epidemic as a few couples I know have split. It's awful for everyone and especially if you have the added stress of a PhD - but I can really recommend a book called "Its called a break up because it's broken". Its very light hearted but also full of good advice - written by one of the script writers of SITC.

It really helped me a few years ago when I was heart broken and thought the world as I knew it was over.

I am so sorry everyone I remember breaking up is s***. Big hugs all round.

I dont have a phd or anything like that... just saw your post, thought i could help give a different perspective. This guy sounds like me... well, in the sense of staying in a relationship for a good while, and having the talk about being "best friends"... I can almost garuntee he wasnt lying when he said it, cause if you guys were pretty good together for 5 years there is an incredibly strong connection. And another thing i can assure you, even if he didnt love you that way, hes hurting nearly as much or more than if he had been broken up with for letting you go.. Maybe it hasnt hit him yet but it will, trust me. Thats all i got to say, I pray for the hopeless and the broken hearted.