shaky from this diet root beer

I'm drinking a diet root beer with no caffeine in it. I am flying around the studio doing literally five things at once... Emailed some galleries, painting sides on most of my new paintings, working on my website, posting to my instagram, and painting a leaf on my multi leaf still life I started last week. This one's going to take me a couple weeks I think. It's because I'm only going to do one leaf at a time instead of working on the whole painting at once. I think the composition requires this kind of attention, and spanned out effort. I'm looking forward to it being done because the first block in layer already looks like a "hell yeah!" in my head. Also, my lower back hurts.