Bloody hell, my sympathies, kidney stones are something I'm massively worried about.
Oof, yeah, that sucks, I've had that happen with my car aswell, I had a headgasket leak but didn't notice it until I had stopped at a supermarket on my way home from work. I went in and bought a couple of things, and when I came out to start the engine it turned over for a quarter second or something and just jammed. Hydrolock. Popped the hood, the expansion tank was completely empty. I refilled it and went home and had my father come by the next day to help check, the tank was empty again... I cooked the engine and warped the engine head, so I had to get it milled, thankfully the engine block is cast iron so it had given basically zero ****s.