I just discovered your writing and wanted to post a word of encouragement but I see that I don't really need to. I totally agree with the gardening metaphor, sometimes energy has to flow back in to recharge our batteries.
I admire that you can do this with poetry. Usually, I can only write it spontaneously when a thought hits so hard i can't find any other way to express it. With that type of work I have no reserves, it's an instantaneous channeling which feels beyond me in both directions.
And just to offer you a bit of a twist, what if it's not your reserves that are burned out but instead it's your ability has outgrown your medium? Temporarily, maybe. I like your nonfiction style, too. Do you write fiction. as well? It's a big lake, and not all the ice is thin. Maybe there's room to challenge your mind even if the dark waters are calm....aw, mixed metaphors, what a terrible way to end this note of encouragement but I'm learning to write more imperfectly. I appreciate you sharing your story it encourages me to not give up either.