You can play chess variants for a change when you feel burning out. I recommend Chess 960.
Variants like 960 were fun for me, but it wasn't because it was different from "chess" - it worked for me because I didn't care about that rating! It is good to have at least one or two categories set aside that you don't care as much about I think; either that or play unrated more. With a category like 960 that you don't care about, you can turn your intense thinking "off" and just mess around for fun and that helps a lot with mentally recharging when needed.
Wow... 1800 rated. I can only imagine how much hell it would be if I went that far in chess.
Gah, most have no idea; it is a lot of work...luckily, time flies and if you keep improving then one day years later, you realize you just made it that far