Feeling negative & emotional & I feel like venting

I'm on period for 3 days now and I've had mixed emotions since. And today my boyfriend decided to go have a drink with his friends he used to work with in honor of a girl who died from overdosing on heroin. I'm not sure why but I felt jealous because he was leaving me out and I shouldn't feel this and I should show love and support. Not only that but lately I've been feeling left out and it's really starting to affect me and I have this depressed feeling just washing over me. I hate that whenever I'm menstruating I become psychotic. I just feel like I'm missing something.