Evening Blues

OK, I had kinda gotten rid of the evening mood swings for a good few weeks there.

But yesterday and today, they are back. Of note:
-both yesterday and today I had small amounts of gluten
-both yesterday and today I have been menstruating
-yesterday and the day before, I had a soft drink that does not contain refined sugar or HFCS, but is made with fruit juice concentrate and definitely tastes sweeter than anything I've had lately

Other than those three items, I can't think of any differences between the last few weeks and the last two days.

I'm not sure what's up... both days were good, productive, fun. Maybe too much media? I feel like maybe I've been at the computer too much maybe?

Any ideas, friends?