This is always so tough to figure out. You run the risk of saying too much and putting yourself in a position to end up in the hospital (as my little sister did once) or not saying enough and really working through or finding answers to what you need help with.
Could you say you tell her that you know you are having paranoid thoughts about people at work, you don't think it's severe but that what you feel would help you best is a break from work to see if this eliviates this trigger until you can adjust meds etc.
Maybe if you come from the stand point of I know that feeling this way is wrong and you have a list of a few things that you need to help with them she would be less likely to recommend you go to the hospital.
I'm so sorry you are feeling this way. I have been there too and ended up quitting my job because of it. It really is a catch 22.