Hey brotha, first of all, I feel for you. And I'd be willing to wager that a great lot of us have been through very similar situations as you have in their professional life, like with your partner, along with your personal life. That being said, extraneous information like that seems to be only for getting attention and pity points to get us to say "screw the b*tch you don't deserve that crap!"
Now first thing's first. Your telling of the way she's acting around patients and other medical professionals is not kosher at all, and I'd recommend having a little discussion about it. Just with what's been said earlier... YOU are the tech. It's YOUR call. It's YOUR patient. And your partner is just that, your partner. They should be there assisting you with anything going on, if you've overlooked something, bring it to your attention in order to give better patient care every time. There is no reason to belittle your partner in front of people, and there is most likely, always a more tactful way to put things. So bring that up to her and hopefully a resolution will come of it. Just remember, a resolution isn't necessarily the ending that you want.
That being said, I think it's time for you to throw on an extra layer of skin. I can completely empathize about the sh*t going on in your personal life. It sounds like you've gone through the ringer and still going through it. But that doesn't make what she's saying/doing personal... and it honestly has nothing to do with it. I'm sure she knows about all the crap going on in your life, if you're as close as you implied. The two scenarios are separate and should be kept that way. Not saying that we don't feel for ya, and want to help you through it, but your situation with your partner has nothing to do with your best friend committing suicide, your mother's passing, your dad being a cradle robber and your ex wife "making" you marry her.
I really hope that you can get a good foothold in yourself and your career in EMS. It's really a fulfilling job if you let it. You will always have sh*t going on in your life, but life is a series of responses and reactions to what goes on around you. You can either become a doormat and feel sorry for yourself, or you can take ownership of your life, and respond accordingly.
Before this turns into a rant, my condolences to you with your loss of friend and mother. I wish you the best of luck with your partner and work.
Be safe brother
D~D