I see no reason to blame anyone here. It's a learning process. The GF for not preventing driving? Come on. We need to take responsibility here.
Here's the lesson you should take like a branding to the arm: Learn to test the moment you feel funny OR if you don't know how you feel OR if someone else says you are acting funny. If you have times you are unaware of your hypo (which is what you are describing) then you need to test
each and every time you drive.
I really shouldn't need to say this, but you didn't come to that conclusion in your original post so it's bit worrying. You're scared - but I'm worried.
There is no other way. Test more, at the times you know you need to - and at those times you don't know if you need to.
