Hey there!
I've been on that rocky ride that you're on right now. I can only promise you that it gets much better. It's sad that AH's or anyone for that matter can come into our lives and make us question ourselves.
Your story is similar to mine. I have never been that low in my life I felt like my life was rocked and I wasn't centered any longer. After I picked up what was left of my life I was more understanding and had a better foundation to "take care of my AH" but do it in a way where I put myself first.
Just remember you're not alone and time is your best friend right now.
Joe