Hi Clara,
Your kids sound absolutely great - and you have so much to look forward to. You also have some major adjustments going on - divorce, alzheimers, aspergers. These aren't small things.
I'm a fellow alcoholic - in recovery five years - with an alcoholic parent and an XABF. The parent had just died when I leaped (divebombed?) into a relationship with the ex. He had recently divorced, was sober (as far as I knew - never saw him take a drink) and was delightful. Then, not so much. I empathize with you completely. With the ending of a marriage, no matter how amicable, your world has just been upended. And it's easy, the more years we have up, to forget how quickly things spiral out of control when we drink. That scares the s*&t out of me the longer I'm sober.
My ex was a big, gorgeous breath of fresh air right after I had nursed then buried my Mom. If I wasn't addicted to him in the beginning, I certainly was after the rollercoaster started and it felt like I needed to "help" him while he got his act together. During a major life change, feeling like another person can take the pain away is fantastic. But he ultimately turned into that pit of need and when I couldn't take away his own pain and wasn't willing to stop my life in its tracks to care for him, he left me and hopped lillypads.
This is a rambler. My point is that this man (and his email was beyond harsh, even if he was making valid points) isn't going to make it all better. You can make it all better, and you know what you have to do - and you're doing it. When you're back on an even keel, you might not be so interested in him. Having limped out of a relationship with an active alcoholic last year, I wouldn't jeopardise my own recovery by becoming involved with anyone in active addiction again. He has reason to be peeved that you lied to him about something that is a central feature of his life. But the way he communicated was mean, and did suck. I couldn't have put that in an email to my ex. I wouldn't want to be with anyone who could be that cruel.
Hang in there, you're back on track and you are so brave for being aware of all your stuff. Just remember to be really gentle with yourself. You deserve it and you're worth it.
Hugs,
SL