Work stress!!!

I'm currently just over 5 weeks pregnant. I had a miscarriage in august so I'm already a bit stressed over this pregnancy. I'm also a special ed teacher with students who can be violent. I've been threatened to be hit or have my face smashed into a door. My job causes me a lot of stress. I'm unsure of how to release the stress. I tend to carry it with me, which I know is unhealthy. Anyone have any ideas to help cope throughout the day?