S.B.
I'm sorry. It sucks to fail a class and to have to tell your parents. It sounds to me like you've done everything you could to pass and the teacher wasn't helpful at all...which sucks. I personally from reading this am bothered that you did all this extra stuff trying to get your grade up and that the teacher wouldn't accept corrections for whatever reason.
Anyhow---that happens though. there are sometimes just impossible to get help from teachers. :(
I had strict parents too and anything less than a C was pretty much failing in their eyes. I had failed a class and had done pretty much all that you have done...which was everything I could think of to pass. I just told them flat out (definitely BEFORE they got the report card). I said I just want to prepare you but I failed this class. I didn't tell you I was on the verge of failing because I really thought with the tutoring, extra credit, etc. that I could pull the grade up to passing.
If I were you I would explain all the stuff you did too and how your teacher wouldn't accept quiz corrections for some reason.
They may be disappointed...but I can't imagine they can be too upset. It's not like you just slacked off and failed.
Good luck!!!