Hi Leasa,
I do completely understand where it is that you're coming from and know exactly how you feel to a "T". Hang in there, take some time for yourself. Then try and find a way to approach the person with how you feel, think etc. I know that it's not an easy task by any means. It's much easier said or thought about than done! But it will open a door for some communication. The person may not even realize they are doing this, or how badly they're making you feel.
As early BP treatment people it's in our nature or charecteristic to "fly" off the deep end. With time, proper medications and cognitive and behavioral therapy you'll find that it does get better. It's a tough journey but if you commit yourself You can do it. I am ever so slowly working my way to that place down that path. Sometimes it's harder I think than anything else I've ever done or had to face.
There's a terrific post around here somewhere called "You are what you expect". I'll see if I can find the link for you. It's wonderful and maybe will give some comfort.
Also this person may be hurting just as badly as you are.
Hugs, We are here for you.
Jeanne