The other day she said she thought I was a hypochondriac or had Munchausen syndrome because I get sick a lot and she thinks I make it up
Is it possible she's
projecting?
If she herself is prone to injury or illness, this could be a possible explanation. Another thing that could be happening, is that all your injuries/illnesses have taken the
attention off of her. My observation with my mom is that her NEED for attention is infinite and insatiable, so when the attention is on someone else, she is uncomfortable, which can lead to saying negative things to them. Just a couple of thoughts.
What I am going to say may feel impossible right now, but I think it would be helpful for your to be able to separate the things your mom is saying to you, from
yourself. If you weren't available for her to say those things to, she would have to find another surrogate to say them to. Could she be dumping her
own uncomfortable feelings on you? What I'm trying to say is I think it's been helpful for me to be able to separate myself from what mom is saying to me, and not take it personally. The first time I heard this, I thought it was nuts. Of course it felt personal. But a year has gone by, and I've grown, and I've come to see its the disease saying those things. Her thinking is distorted, and I don't have to believe what she says as truth, because it's not. If I wasn't here, she would be saying them to someone else, because those are uncomfortable feelings that she has to dump onto
somebody. That's how I think of it as not being personal. Furthermore, to protect yourself, you can continue to practice some boundaries so that when she starts saying hurtful things, you can say something non-judgemental like: "it seems like we're both not feeling well right now. I have to go now, and we can talk again when we are both feeling better." Then give her a few days to sit with it, and look after yourself. When her emotions are not intense, and she's not dumping, and she's not projecting on you, that's when you could use an "I statement" to tell her it's not ok to say hurtful things to you (give her a specific example). Then set your boundary and tell her when that happens, you will have to leave. But only set such a boundary if you can follow through with it. When I know my mom is dysregulating, my plan is to have my H with me when I have to interact with her. Do you have anyone who could be with you when you visit your mom? My mom only abuses me when I am alone with her. Maybe none of those things will work for you, but they're a few things that I've tried that have worked for me. Different things work for different people, so I'm not sure if that's helpful or not in your case.
berated me for being 31 and unemployed.
I wouldn't even respond to this kind of thing, because it just reinforces her for creating negative drama, and makes you feel like you have to defend yourself. You don't. Defending yourself makes her feel more powerful. It kind of sounds like maybe there could be a power dynamic going on here. Instead of replying to such an uninvited accusation which is destructive to any relationship, tell her you are happy to talk if she has positive things to say, but her negative hurtful and judgemental comments aren't helpful to any relationship. If she wants to be helpful, she can say something positive, or say nothing at all. And then say goodbye and hang up or leave. That's my thought. You can choose not to listen to her insults, judgements, and accusations. That's a boundary. I've actually done this in the last year, and it's been helpful.
I'm thinking about getting my doctor to zoom with her and me to explain my condition to her, which I shouldn't have to.
I would not do this. I think what you are thinking about here is JADE (justify, defend, explain) and it won't help because they only hear what they want to hear, and she will find the whole experience invalidating. This would only help if she was emotionally healthy, but she is NOT. So treating her like she is healthy, could backfire. Furthermore, you will have sacrificed your right to privacy, and she may use whatever information she gets from the doctor against you at some future date. I think you would strongly regret this afterwards. You also mentioned you should not have to get your doctor to zoom with her, so that suggests you have a value of privacy. Don't break your own privacy boundary, is my suggestion. Hold your boundaries, and your private information. Don't give it away to her.

I'm doing a class for PTSD
good for you!

Stay strong. You have a T. You acknowledge you are making progress, but it sounds like you are wanting to make more progress. Some things can't be hurried, and we have to be patient with ourselves as we keep up our good work towards recovery. Self-care cannot be overstated. My mother trained me to always put her needs and everybody else's above my own. Now at 58, I also have finally learned how to look after myself. The more I take care of myself, the stronger I am to manage the interactions with my mother.
Self-care, self-care, self-care, and limit interactions with your mom if you need to (as part of your self-care plan). Just tell her you need some time to look after yourself, and let her deal with her own feelings. If she "pushes back", tell her you have to go. The only way she will learn to treat you better, is if there are consequences for her bad behavior (use positive and negative reinforcement with her, just like you would with a child).
I know the fear you are talking about. I too am terrified of my mother, especially when she's dysregulating. But it can get better. You can do this.
