This was a great topic to read, congratulations! it sounds like that was a victory and for all you might not be able to let yourself think as much, it does count.
Just in case you want to try music again, bare in mind reading music is very much an optional extra. Usually in those sorts of groups the pianist or similar doesn't mind note bashing someone's part. I've actually had occasions where I've been in choires or similar and people have remarked that after seeing me learn stuff without reading printed music they felt a lot more confident trying that themselves, and in doing that found things a lot easier since they weren't grappling with a lot of signs and lines and what not that was knew to them and could just listen to the notes, heck if you do any on stage performances in musicals, opperetas etc the first thing the conductor usually says when you get past the first rehearsal is "books down"
So, just because something is the expected way of doing something doesn't mean you have! to do it that way at all, and if another method is more comfortable for you, well you should let yourself do that.