De-stress

Cynthia • 30 years old and have a wonderful boyfriend, Bryant, and a 10 year old beautiful little girl, Alyson.
How do you calm yourself about workplace stress? I love my job. I love almost everything about it. However I have a strong personality. I try to keep that in mind of course but it seems that my general manager and I have butt heads a lot lately. I spoke to a supervisor and she mentioned that sometimes people do things intentionally to get under another person's skin. She was eluding that he was doing that just to piss me off. Well, I'm almost 8 weeks pregnant and very high risk. Any idea how to just not let him get to me? Sadly, he's both the type you can't sit down and talk to Bc all he will really do is blow smoke up your ass then wrote you up for something stupid later. (I know this Bc it's happened before.) 
I changed 1/2 of my work schedule around for this current week that ends tomorrow to help out the company since one of my coworkers are very sick. And in return, my GM cut my hours. It wasn't by a lot but we don't get state help and it's already hard enough as it is. 
I just want to be "happy" when I have to work for him and when he asks how I'm doing, I'd like to say "good" and shut up from that point on. Any suggestions? Sorry, I really needed to vent!