Congrats on #4! Working & going to school during any pregnancy is going to be stressful, all I can say is ur a lot stronger then I am. To handle stress I take a warm bath & turn the music up so I'm in my own little world. If I'm not home, I using my note app and just write down everything that's making me angry & take a few minutes to take a few deep breaths and calm down. Good luck Hun & I hope things start getting better for u.
May sound dumb but walking has always helped me and if your Moody I suggest keeping a journal at night to clear your mind so you can sleep much better. Wish I could be more help!