Dumped by my boyfriend. Two months later, still fucking hurts. What can I do to heal even a little bit?

I know this sounds very "woe is me", and I know almost everyone goes through this, but him and I share all the same friends so it's difficult to get unbiased advice.

A bit of background information, I am 22 year old (gay) man and he is 40. We dated casually for about a year then I sort of fell in love with him, and we were in a relationship for a year after that. I seriously thought we would be together forever. We have traveled, gone to weddings, and done all those "couple" things, but despite me spending more time at his place than mine, we (fortunately) never actually moved in together.

One night, we had a nap in the afternoon/evening (we spoon very close while we sleep), and when he woke up, he broke up with me. I cried, and cried, and two months later I still do. It's all I can think about, I feel like I still want him back, but I'm so angry with him at the same time. I've tried talking to him, I've tried avoiding him, I've tried talking about it with friends, but nothing seems to help.

I'm asking because this seems to be taking over my life. I do research in mathematics and statistics, as well as do a bit of teaching for work, but my concentration is severely interrupted. I can't eat properly, or even sleep for more than two hours at a time. Alcohol, drugs, nothing helps. I've always considered myself a rational and intelligent guy, and now I see myself as a whining teenage girl which only makes me feel worse.

Any advice or personal stories are highly appreciated.