I want to say thank you to everyone who's replied. You have all given me a warm welcome that has made me feel safe and heard here, which has been hard to come across elsewhere. I could not thank you enough. This platform has given me a small but major outlet to express the fears I've been thinking about and the way I feel, which helps me feel so much better, especially with people hearing and responding.

To update...
I have been feeling better about my health mentally. I've been able to eat without issues the last two days, and I no longer vomit at all, nor do I wake up shaking (though I do still wake up early to use the bathroom..). My appetite has returned to some level even if it's still kind of weak compared to my fully able self; that is to say, I feel hungry when I think I should, especially when I think of eating.
Today, my neck started feeling pressure. I may have slept wrong, I don't really remember, but it is accompanied by pressure in my forehead that I have been feeling the past 3 days. It's completely painless both in my forehead and my neck, aside from the first day it was present where I had a small headache towards the end of the day. When I shiver (which is pretty frequent) the neck feels a little worse. It does not feel like migraines I've had in my life, but usually migraines are pretty debilitating to me. I don't know if this is normal as well, and of course my frantic mind finds some way to panic about it being related to a tumor... of course I should at the very least doubt that. I should note about my neck that my posture hasn't been the best, I've been looking down a lot at my phone which probably isn't helping.
So in some ways I'm feeling better, in other ways things have been the same. I just hope I can feel normal soon. Since this all started it feels like there's some kind of barrier between me and the real world, it's hard to motivate myself to do anything. Everything terrifies me and I'm so scared for what is going to happen in the future. Tomorrow is my first doctor appointment out of the 3 I have in the next 2 days, with the other two being a lab and an online appointment with someone over at FOLX.
A couple days ago when I was feeling especially panicked, I made a list of my symptoms both to be able to remember and present them to the doctor without scrambling for my words when I get there, but also to be able to research and draw every symptom to high or fluctuating estrogen to reassure myself and remind myself that, in all likelihood, it has to be traced back to what happened (almost) two weeks ago.
On the list, red means it's still fully present, yellow means it's gotten better or improved in some capacity since it started, and green means it is completely gone!
(I should reiterate, I am not saying or showing any of this out of a hope that someone will give me genuine medical advice or an expectation that someone should tell me with any professional authority what they think is happening. However, if anyone does have any input about how they think these symptoms are normal, are familiar with or heard of them with other people like me, or even that they have experienced it themselves, I would really appreciate to hear that!! It has helped so much so far just to be assured that what I'm feeling is totally possible and likely for my situation.)