Here's a different framing that might help:

Diabetics are normal people who happen to have a chemical deficiency that requires constant monitoring and chemical intervention. Some days diabetics will struggle to participate in society at all because of sugar level management.

You're an emotional diabetic, just like me. I've got my emotional insulin tuned pretty well but there are still days where I struggle to find the willpower.

Give yourself the space and the grace to have down times, especially since you know during up times you'll enjoy what you do. See if there's any self care you can do to make the down times less bad.

Good luck brother/sister.