OP - This woman is miserable and sees that you are happy in your life. That is why she is picking on you. Not only that, but it seems that she is getting a "rise" out of you and, in doing so, is bringing you right down to her level.
Go ahead and call in sick, so that you can go shadow and get a new job. That's the only way you are going to leave her miserable behind, well, behind. What does it matter that you are going to have to deal with her nonsense for another couple of weeks? What's a couple of weeks when you've already been dealing with it for a lot longer than that?
Also, I would just tell her nicely, but directly, that you will no longer deal with her attitude, that this is a place of business and that you would prefer that she treat you professionally and respectfully. If she starts slamming stuff around, get up and leave. If she says something nasty to you, tell her that you will discuss this with her when she can be nice.
Good luck! And be sure to go shadow, no matter what!