I think Katya actually has a point. Not necessarily that you need to leaven the sweetness the rest of the month, but this jumped out at me before I'd read her response:
Montana wrote:I end up snapping at my son and my mother (who I live with) for things I would normally let go and then I end up filled with guilt.
Not "for ridiculous things", not "for things that don't ever bother me," but "for things I would normally let go." I read that as, normally they annoy you but you let it go, don't make a big deal out of it.
When I have PMS, that's how it tends to manifest itself, too -- I get mad about perfectly reasonable things, it's just that they don't always make me mad.
I just see it as one of the many ways that our bodies and psyches self-regulate. I don't think this happens just to women, btw... my husband has (OK, have rejected the word "periodic" and "his periods when...") occasional hissy fit (gawd "period" again um) episodes or short stretches of time when he is less tolerant than usual. Like fine fine fine fine then ACK!
From what you said, the main thing I think you need to focus on is what you do blow up about and why you blow up about it. If it's things that are legitimate and you are being a saint the rest of the month, go ahead and let your family know you're human, and have limits, and if they don't want to get blown up at, respect your limits.