The actual act of exercise is pretty miserable for most of us. It's the hours in between exercises that for better, for me. I just generally feel better when I'm exercising more.
It sounds like you're getting plenty of exercise, so it's time to check into vitamins, meditation, mindfulness exercises and whatever else.
In your shoes, I would keep exercising, to keep that variable controlled while I tried the next change.
Uh... So no gift. Got it.