My heart goes out to you.
My friend used to simply retreat, too.
Her personal pain was so very deep.
Some parents have to work their way into acceptance. Unfortunately, that time-frame of your mom reaching acceptance is a time when you are not feeling fully supported by her.
Many years ago, I worked with youth suffering mental illnesses. When parents would come in for family meetings and their teen child would tell them how they'd been suffering and the doctor would confirm diagnosis(es) to parents; many parents would protest, stating their children were drug addicts, not suffering any mental illness.

(Their children were not drug addicts. Their children were suffering and parents were not ready to hear/accept what was really going on.)
We did find it was helpful for parents to hear directly from their children, as to how their child had been suffering. We'd also found that when we told the parents the parents were not to blame and could offer hope, parents usually came to acceptance sooner. Of course, there are always exceptions.
We had one father blatantly refusing acceptance, because he'd felt if his son had bipolar illness, he'd passed the genes on to his son, which is something he'd never do! Do you see the irrational reasoning? The father was a bright man, too! (Of course he cannot consciously choose which genes he passes on.) He could, somehow, deny his son's struggle this way, which was, somehow, comforting to the father, yet so very invalidating for his son.
You might take a risk and let your mom know you truly need her validation and support?
It's very important your family/friends learn about your experiences and your needs, in order to validate your experiences/needs. You get to choose who you let in on that level. I very much wanted to know more about whatever my friend experienced/needed and I consistently ask, as she has an ingrained habit of just retreating and suffering alone. It's getting better, our ability to relate/understand, as well as to respond to, her inner experiences/needs.
There's a lot of hope!
Some organizations offer education for family members/support systems.
I hope things get better with time.
We are here to support you, too.

WC