I'm worried

I'm not sure what to do. I'm a LPN in Nova Scotia Canada. My job is very stressful, I work on a locked ward with dementia/alzheimers patients. I get hit, and spit on and abused daily. My job is stressing me out to the point of tears before each shift and I've even gotten physically Ill before shifts, its putting a strain on my relationship as well, I'm always irritated and lash out on my boyfriend because of the work stress. I dont know how much more of this I can take. I want to take a stress leave, to give myself some time destress and see a therapist but I dont how to explain it to my family doctor. I'm worried he will deny writing me a leave of absence note. If I don't get time off I'm scared about what will happen, I know I cant take any more abuse. It's not fair to the patients or to myself. Please any advice will help