I don't have a particularly bad form of ADHD, thankfully, but I can still feel the struggles I'm reading in this thread to my core.
My biggest killer is meetings. Especially the boring, pointless kinds that have nothing to do with my actual work (like the one I'm sitting in right now where they collected everyone in the product team to ~look forward to 2023 and what your role in all that is!~ (please shoot me)) that drag on for what feels like eternity, slowly sucking away any and all excitement about the day out of my life.
It transports me back to primary school, where you were stuck in a room with no escape for a large chunk of your day. If I had absolute power, the one thing I'd do for those like me with ADHD would be to make meetings over 10 minutes illegal and punishable by a Ludovico Technique style torture method, let's see how they like it!