First, let me preface this by saying that if you truly feel that they are wrong, and way off base. And that you ARE 100% capable at this time of taking care of your dc, then yes call the cops ASAP!
And now I'm going to play devil's advocate. Don't hate me too much please?
I have a mental illness, too. And I've battled off and on with it for YEARS. Different meds, different diagnoses...all that.
Sometimes, I am a really crappy person. And mean, and angry. And usually, when I'm in that place....I don't see it. B/c of course, it's not MY fault(in my mind), it's everyone else that is effing awful.
And honest-to-god, if I was in a bad enough place. I know my mom well enough to know she would grab me by the shoulders, shake me, and tell me to get things together before I took the kids home. Now, she might try a gentler approach first, but yes, if she felt I was bad enough, she wouldn't let me take the kids home. And I'm okay with that, b/c I'm not...me...when I am there.And I would rather my kids not be with me, if I'm that out of control.
Now, I'm not saying that you ARE at that point(b/c I don't know you or what you are like normally) but is it possible that they aren't doing this to be mean to you, but because they are ACTUALLY concerned and ACTUALLY afraid that you will "snap" so to speak?
I mean, if I was worried about that, and then the person I was afraid would cause harm had a "heated discussion" for hours which escalated into threats by both sides to cause the cops, that would kinda confirm my fears.
Like I said, just playing devil's advocate. I'm sure it won't get me much love on the boards, but...
I don't know you, I don't know your family, or what kind of relationship you have with them.
Like I said, if you are sure that they are completely off-base and in no way right, and that you ARE capable, please do call the police ASAP. And I second PP's suggestion to have your doctor's number ready.