It very well could be your meds. Messing with my meds puts me on a roller coaster every time.

I remember when I first got diagnosed and the whole med thing began, I could be in a normal mood in the morning, hypomanic by late morning, super anxious mid-afternoon, then depressed from early evening on. I just did a med change and dealt with irritability and hypo symptoms caused by it. Things just calmed down now after about 4-5 weeks now that my body is getting adjusted.