I can relate. I've been in a weather-induced dysautonomia flare for the past four days and my energy has been dwindling by the day.

I went to bed early last night, rather than keep gaming with housemates and friends on Minecraft, but though I managed to sleep the entire night through, I was not able to get out of bed this morning — not even to use the bathroom (though it wasn't urgent) — and ended up sleeping another four to five hours, so didn't get up till after noon. In total, I probably slept about 15 hours. Anyway, it was all I could do to make myself shower and get on the computer now.