Emotional rollercoaster

I know that with anxiety and depression you have good and bad days. I've been having alot more good days since my doctor changed my medications around. But I woke up today feeling really down. I don't know if I was tired, depressed, or just having an off day. I managed to pull myself out of bed, get dressed, and eat something, but I have felt worn out all day. Like I have no energy at all. Any one else feel this way sometimes? What do you do to cope?