Is it normal for your happy energy to drain throughout the day?

So this happens every day.

I wake up happy. I feel energetic and ready to take on the day. I am enthusiastic and have a bunch of plans for awesome stuff I am going to do after work.

But throughout the day, that feeling steadily depletes. My happiness and energy I once had, by the end of the day, leaves me feeling cranky, angry, and easily irritated, along with muscle aches and pains.

It is a steady decline. Think about those little 'how are you feeling' slips you get from a doctor. Those pain evaluations you get where 5 is happy, 4 is pretty good, 3 is decent, 2 is not feeling so good, 1 is pretty bad, and 0 is completely miserable.

At 8 o'clock when I wake up, I will feel like a 5. At 10 o'clock I feel like a 4. At 12 noon I feel like a 3. At 3 in the afternoon, I feel like a 2, and at 5 o'clock I feel like a 1. By the time 6 o'clock comes around I just shut myself away in my room and sit in misery...

This is really affecting my life... For I wish to go out and do things after work... But all of my energy amd happiness and inspiration is gone by the time I get home.

Is this normal? What do you suggest to keep my happiness and energy up? Thank you in advance.