sis's baby shower - girl issues :/

So tomorrow is my sister's baby shower. I'm meeting her bf's family for the first time. I don't really like being all happy smilie social. If I have to, I will. Prob is, it's that time of the month. So I'm most likely going to be an emotional wreck tomorrow. So I pretty much need advice on how to keep mood swings under control, prevent cramps, be happy smilie for about 4 hours, and do it without being able to shove chocolate down my throat the entire time.

If you're a girl, hopefully you get that it's almost impossible to keep mood swings under control. It was horrible when I was at school and would just break out crying. I had to be like "oh I accidentally jabbed myself with my pencil..."

I love my sister but I don't know which one of us is gonna be more emotional. She's 7 and a half months pregnant. I have anxiety probs to begin with and that time of the month just makes it that much worse. I'm willing to try just about anything to make it through this. It's gonna be about a 2 hour drive to the place they're doing it btw. So I also have the ride there to add to making me nuts.