Energy, or diligent effort, is the second kind of happiness. Putting forth effort, generating energy, getting things done, keeping after it and feeling good about your accomplishments is a wonderful way to be happy. It is also a tricky kind of happiness, especially if you live with chronic illness. Let me give you an example.
The Second Happiness--Gone Wrong
When I was very ill, I had a half dozen doctors in a row tell me there was nothing wrong with me--boy were they wrong! I should have had faith in myself, and treated myself with more respect. Instead, I misused my energy by doing things I KNEW would make me worse. Basically, I would provoke attacks of paralysis so I could reassure myself that I was right. I did a great job at reassuring myself and being right, but I was also miserable and in horrible pain a LOT.
That was NOT the right way to be diligent. That was using energy to make myself miserable. That was self-abuse that was at least as wrong as the abuse I took from doctors. Yeah, they couldn't diagnose the difference between a rat and a mouse, but I was an idiot!
Put YOUR energy into things that make you feel better. Have faith in yourself. I guarantee you'll start feeling better just as soon as you stop hitting yourself in the head with a hammer.