Wamama.....you are not a bad callous person....otherwise, you wouldn't be crying.....
Everyone has...or Should have....limits of what they can and will tolerate from other people. Even people that they might have loved.....
To me, that is what boundaries are all about. We all need boundaries, in life.
It sounds, to me, like you have reached your limit of what you can live with, without totally...completely...losing yourself.....
personally,I don't see that as a point of dysfunction--I see that as being a normal person...who still has a shred of self-preservation left...lol.....
Being in a relationship...or marriage...no matter how long...does not automatically condem us to a life sentence in "emotional prison".....
this may be the hardest thing that you have had to do...but, it may be the best thing you have done for him...ironically....
Just like, we never know how much strength we have inside of us...until we have to use it....the same thing applies to him!! Always--we have to be pushed up against the rock to find this out......
I'll bet that you have let him slide a million times, over the years...?
does anybody let you slide....?