Could you add a region tag? This sounds like a situation where you might benefit from additional resources at your university, the names and framework of which vary a lot across countries.

"I have obviously thought about this a lot and it's what I want to do." The "it" presumably refers to continuing your PhD, didn’t it?

A lot of what you describe would be absolutely considered as discrimination in the UK. "She also said that she's finding my health problems a bit much to handle". This should not fly, and I am absolutely shocked at some of the answers given below. Depending where you are in the world you should contact the student union or the head/dean to discuss about what you faced.

Can you clarify that third paragraph? I can't quite tell who was for and who was against the extended Covid-related break, and I can't tell what does and does not extend the timeline clock.

Having 12 PhD students concurrently is the biggest red flag. A good researcher may be able to supervise four students tops. They clearly don't care about you: they see you as a paper making machine operating at half capacity. Work on your social skills first amd switch to a supervisor that cares about you as a person first and foremost.

@Okano Contact them to achieve... what? To force somebody who doesn't want to work with the OP to work with them? Do you really think the OP would get a good PhD experience if their supervisor was forced to work with them? Whether they were fair or not in their decision (and it does sound like the supervisor was cold and insensitive), I do not see a point in trying to force a working relationship in this situation -- the OP would be much better served by finding somebody who wants to supervise them.

@penelope "Contact them to achieve... what?" To report discrimination? I have lived in 4 countries and all 4 of them this behaviour would be punishable by law. You are putting words in my mouth, I never said that they should continue working with them. Letting this fly is exactly why some institutions ends up in terrible states. "Just move on", "Don't ruin your career" these words are pronounced too many times on this stack, often for situations that are much worse than this. This is unacceptable.

Are you in the US? Also, why did you choose this university?

I just want to say sorry you have gone through this. Your supervisors should be supportive of your development. Some of their comments show very little empathy for what you have gone through (particularly the "yes, but you know how the biopsychosocial model works"). Well done for getting a systematic review done while all this was going on. I think there are much better supervisors out there, I would consider finding another one.

@Okano Appologies, I really didn't plan to put words in your mouth. And that would indeed be a good reason to get in touch with somebody in a position of authority, and something they may be able to address. However, the OP was asking about continuing her PhD, and I tought your comment was to that end. The OP would be absolutely in the right to pursue this as a discrimination case at her institution. But while that would go towards addressing the problem of the injustice she has faced, or maybe getting some much-needed support, it would not go towards improving her PhD situation.

@Okano Should we be in a position to persue our passion and address injustices done to us? Absolutely. But this is not always the reality. It's easy to get outraged online, type "you should report what you faced", and be done with it. In reality, reporting this would likely be (yet another) long slog, taking time and effort. Somebody with health problems, working part-time as a psychologist, and (potentially) looking to secure a new PhD position likely has a lot on their plate already. Reporting discrimination should absolutely be an option, but not an imperative as you make it.

There is a lot to say in this situation, but the most simple direct piece of evidence I can give is that you find a new PhD supervisor. It sounds like you are fairly early in the PhD so you have time to find another supervisor, but you need to do it fast.

@penelope This would require a deeper conversation outside the scope of stack comments. Let's agree to disagree

You could contact a lawyer for legal advice. Have discussions with your supervisors by email, or document your past conversations in an email, so there's a paper trail.

I don't understand why this story triggers so much support, in the form of up-votes, comments and long replies expressing sympathy for the OP. Because it feels genuine, because it is recognizable? There have been similar posts at the forum, and the response from the community can be dismissive or indifferent.