Employer is awful

Hey im gonna try to keep this vague but also specific enough to get answers to my questions. I work a minimum wage job with a union. My manager is overall super difficult but besides that I asked to reduce my hours a few months ago. She said I could not because I hadn't worked enough hours to change my availability. I said okay. And I then I requested information on how to request accommodations for a diagnosed disability. I asked for someone else's email because I was not comfortable talking to her about this. She said talk to the head manager. I said okay can you please give me her email? She said no, talk in person. So I said I would feel more comfortable using email so I can document it. She refused to give it to me. I said okay then what is HRs email so maybe I can talk to them. She said no. She won't tell me. She then claimed the union rules are to not give it. I was like let me get this straight, the union says that employees are not allowed to have HR information? Is that correct? Her response was then "just talk to __ managers name __"

I can now find the HR information somewhere else but that is besides the point. I ended up dropping it because I was and am exhausted and burnt out. But whenever I tell people about that and they say how shitty/ maybe illegal it is, i wonder what I should even do. Is there any point in pressing the issue or telling someone about her withholding information from me? Where do I even start? I still am employed there, dont know how much longer it'll be sustainable at this point as its a shit show there.

And yes I will add i am super thankful I have a job in these terrible times and lots of people dont have work. I am grateful. But also I feel confused and disrespected.