The roller coastery part should have been kind of a tip off. I know you would like to believe that love can conquer all, but when you start hitting those negative bumps and try to push through them or sweep them under the rug it is just building up. To the point where a man of 28 years just calls you by cell and tells you it's over. To the point where detachment becomes one hundred percent complete and he has no remorse and has learned absolutely nothing other than "you aren't the one for him".
While he has been completely and utterly wrong many many times I imagine, you have to understand that you contributed too. Maybe you turned a blind eye to a few things or downplayed some other actions. For 28 years, you must have a long laundry list. What has happened has happened, but I hope you have a book's worth of lessons out of this long, harrowing experience. It's a difficult feeling that you probably can't get your youth back or what you had before, but this is not the end of the world. There are many people that can you will find happiness with, and lord knows that they are much more mature at this age than the age at which you started your relationship 28 years ago.
Write it all out, talk about it, get angry, go through all the emotions. Finding your release is key like many have mentioned above.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.