You know, we are human, and we are fallible. Don't beat yourself up. Of course it is hard to say good-bye after spending 25 years with someone. At least you realized what course you were on and were able to catch yourself before falling too hard.
It is hard to accept that someone is just who they are for me. I see this person in front of me and I have all these ideas about how they should treat me, BUT, I cannot for the life of me get him to be how I want him to. I just can't. If I could will it, he would be a prince in shining armor, would have an awesome job, would support me in anything that made me happy. It just isn't so. It is never going to be so in my case, ever. He isn't the kind of man who I envision myself with for the long haul because I can't change him into someone that treats me in an acceptable manner.
I think this process is all about discovery of ourselves because we have essentially given our souls over to this other person for safe keeping. (Or at least I did). My ABF doesn't care about me, he cares about alcohol. I should never have entrusted him with a part of myself because I knew it wasn't safe. I went against my own gut feelings and the words of those who truly DO care about me. I used to be very confident and I gave my life over to the disease of alcohol. Just keep enlightening yourself, keep searching, keep being your own beacon in the dark. You are going to be just fine!