Ha! I totally understand your (NOT you’re!) angst. I am a self-confessed “grammar nazi” and subconsciously proof read everything (including billboards!). A grammatical or spelling error will jump off a page without me even looking for it.
(That’s not to say that I don’t make the occasional typo…)
But seriously, as long as you can get the gist of what people are saying, try to just let it slide.