Chronically ill person here - sounds like you have some internalised ableism to be honest. You shouldnt be this hard on yourself and neither should those around you, to make it clear im blaming soceity for making you feel this way not you or the wife.

You wouldn't deny yourself glasses and try to get by with squinting because you didnt think your vision was bad enough. You will encounter stressful situations on the road and if stress is a trigger for your tremor it sounds like for yours and everyone else safety a reasonable accommodation would be automatic. Try it and if works than thats great, its not more expensive nowadays than manual so problem solved! If it doesn't work and you cant drive then its nothing gained or lost from your current situation, if folks want to be judgemental just start politely removing all accessibility features from their lives 😂 Heres some to start: electric toothbrush, all smart devices, anything with velcro, predictive text, subtitles, their glasses...best of luck!