AITAH for quitting my job?

My former employer, manager and I had our checkup. They do check ups with everyone in the company.

During this meeting the management asks us a bunch of questions to see how we are doing. One of the questions they asked me was how I was doing with having my other job on top of working for them. They also asked how I was balancing work with dealing with Multiple Sclerosis. I mentioned that I had recently left my other job because of remarks from my team lead about my disease.

In response to this, without telling me or asking me, they deleted my availability that I had marked off so I could work my other job because they assumed I wanted more hours.

Then they scheduled me for an event that is about a month away without asking me again.

I disclosed to them that I wouldn’t be able to be at the event because the event is scheduled during what my availability states I am unavailable for.

In response to this my boss called me and ripped into me saying that I have no loyalty or care for anyone else on our team because I am going back on my word.

Of course, with almost all employers, there are quite a few different issues that I have had throughout my time with their company. So maybe this is just the boiling point.

Anyways, am I the asshole?. I really don’t know. I feel incredibly disrespected tbh because this event was going to prevent me from taking a second job which I need and the company couldn’t offer me the amount of hours I need so I wouldn’t have to take a second job. In addition I schedule doctors appointments and stuff during the time that my availability blocks off for me.