Now I'm tired

So yesterday I was ready to nap on BART going to SFO. Today, around noon and then around 4pm I was ready to nap. The scary thing is I was driving home from the dog bath place in PB (yes, per the vet, Frankie needed a medicated bath!), right when traffic was starting to get heavy. Even waking up this morning was harder than it has been for the past week. I wonder if my meds are finally leveling out and need to be changed again, or perhaps all those mornings when I couldn't sleep more than 4 or 5 hours last week finally catching up to me?!?