I would have said much the same as @SassyBoomer .
There is something in us that will always crave something from our mother to feel unconditionally loved, safe, and secure. And why not? She is our mother.
But mothers, in the end, are just people too with their own pain, sorrow, trauma, etc. Try to see her in that light here. You may never get what you need from her. Allow yourself the space to mourn the loss and try to find acceptance of it inside of yourself.
Don’t mention your sobriety to her, but instead let your actions inform her of your success. Try viewing her, in a way, as a stranger that you want to befriend and try a different tactic to connect with her If possible.
If you really want to try something new, when she is critical in the way you discribe, try agreeing with her and adding an expression of appreciation or love.
Ex:
“I hope you can finally stick to it…this time…”
“I hope I can too. Thank you for the encouragement. You are so good at sticking to your goals. How do you keep on track when you’re trying to succeed at something that is hard for you?”
That’s something of a bland example, but the point is there. You can’t be rid of her because she’s family, but you can decide to change the dynamic. Get encouragement elsewhere. Seek acceptance and understanding elsewhere. See your mom for who she is as a stand alone adult and try to approach her without those wounded desires to be understood and accepted simply because you are her child.
Also, if you don’t have a psychologist to talk with, i would recommend finding one. A good one you feel comfortable with.
Im not sure how much of that is useful, but take what is and leave the rest.
Edit: you mentioned therapy while i was writing. Good for you. And @SassyBoomer is right that no one has to be in your life, but cutting off family is hard. Necessary at times, but still hard.