^^ that's a lot of pressure and high stressful situations and change and uncertainty all happening at once. It's like in your brain you're stacking lots of balls on top of each other and trying to make them stay in a tower but they all will fall and roll about in there because it's all a bit too much to process and deal with all at the same time.
As for being a horrible partner/friend/sister/daughter - that feels like it's really hard to imagine someone thinking of you. It might help to reframe that as what's happening to you right now is a lot to experience and it's putting up a temporary barrier between those relationships. It's okay not to be emotionally or physically available to others and the people who love you will know that's what's happening. Also it can help to reach out and let them know when/if you feel able to, as they might be able to offer some comfort. Offloading really helps just to get it out and if you think perhaps talking to a counsellor might help that sounds like would be a really good thing to do.
It's okay to feel like everything is too much because sometimes it is, but it won't always feel like this all the time. It's only when it passes through us that we see that though, of course. And it will pass
