Short tempered

I have noticed that lately I have been so short tempered with my boyfriend. Little things (that should not make me mad) sets me off so bad. I get so angry or sensitive. I’m a total cunt sometimes while others all I wanna do is tell him how much I love him. I don’t know why I am so short tempered lately but I feel terrible about it and I just wanna know if anyone has tips or anything to help because I try so hard to stay calm but it seems to never work