Mystery Man said:
Three years of solid, every other week DMing has melted my brain. I'm taking the summer off and coming back into it starting October.
Any advice to recharge those DM batteries?
I think the most important thing is to take some time to think about what it is you actually want to do, which parts you enjoy and which you don't.
Then when you come back, try and organise a game around the bits you like and minimise the bits you don't. In extreme cases this might even mean getting someone else to DM, playing core rules only, or playing Mutants and Masterminds instead.
Also, make sure you are interested in the setting. If you are into swashbuckling movies, run a swashbuckler campaign, for example. As your interests change, change the focus of the campaign.
In my case, I don't have the time or the energy to prepare detailed notes ahead of the sessions, so I keep most of the plot in my head. My notes for the session tonight consist solely of the stats for quasits and retrievers, copied out of the Monster Manual, and the name "Desatio". (And I don't really need the name written down, since like all my NPC names I stole it.)
The game would run better if I prepared fully for each session, but our group is very social, so they prefer me to largely "wing it" each week rather than have a meticulously prepared adventure but only meet once a month.