Anxiety

I have anxiety really bad. it's so bad I get sick physically and can barely function. I am a mother of 3 and sometimes it affect me taking care of my kids. Today I had an episode.. My son who is 4months old, his father was coming to visit. You see I still love this man and we've been through a lot to now we're no longer dating due to his infidelity. so he was coming to visit today with our son he was suppose to come around 6:30pm and he didn't show until 8:30. I have a rule about him coming after 8, he can't. I have my son on a schedule and frankly why are you coming to my house at this hour anyway?? I was soooo mad to the point it bothered me and my nerves were shooken. I literally had to take my meds and lay down for 30 mins to calm my nerves . How can I learn not to get so upset to the point I can't control my emotions?