Is this just me?

I'm an overly dramatic person, I can admit it. I often get worked up about things that aren't really worth it in the long run, or form an instant disliking for a person that turns into gut wrenching hate.
Which is the situation here. Gut wrenching, acid filled, bring on the ulcer disliking for a person. Who I happen to work with and can't really avoid or ignore. I've tried, oh GOD I've tried, and this morning when I first went in to work things were going to well that I thought "Oh, I'm not going to have to go to the managers about this". Then she reminded me ever so clearly why I despise her.
So imagine crazy busy work time. Customers overflowing and everyone has to bust their butts to keep up. I call over to her "Hey, when you are done with that can you come help us" she looks up and tells me "I'm going to take the trash out". Customers OUT THE DOOR and she can't be bothered. (Which wouldn't be that big of a deal if she weren't constantly slacking off and putting the work off onto others.) Then later she asked a question, and when I answered she looked me straight in the eye and said "I refuse to answer to you".
I've been there for over a year altogether, and while I may not be a manager it's only because I turned down the promotion, and despite that I have seniority on her and WHERE THE HELL does she get off talking to me like that? In front of a manager? Who oh, by the way, didn't call her on it which just made it feel all that much worse to me.

I like the location I work at, but there are two other stores in town that I could also go to since our owner runs them all. I don't want to leave the people I work with, but since none of the other stores will take her (after she walked out on a shift she was "fired" until the manager at our store said she could have another chance. But only our store is willing to provide it) I'm going to have to be the one who takes the cut in the hours or the transfer. Because I cannot work with her. The stress is making my physically ill and it's just not worth it to me.
So now I have to lay down my semi-ultimatum (I'm really not saying it has to be me or her) to my bosses who are already amazing about working around my availability, but how much are they going to put up with? You can't waltz in and announce how things are going to be done when you are there. Although this bitch has done it and no one else at my store seems to see why that is a problem.

So I'm wondering if this is just me overreacting? Am I the only one who can dislike people so much it causes illness? Should I just suck it up and be an adult? (Though I've tried, really I have and that just isn't working) Do other people get this angry? I never know if it's how people are, or just me and my disease.
But I have to stop ranting now because my stomach hurts.

Edited to add: I've spoken with my manager and will no longer be scheduled with the bitch. I won't be losing hours. Makes me wonder which one of us will.
Also? I started my goddamned period again. The first time I went off Depo this happened but I was able to fix it by going on the pill because we didn't know then that it could kill me. Now I just get to deal. Lovely. Explains my emotions for the past few days though.