Congrats on the very large improvement...however....the RC is extremely important. I don't know how admissions will look at it...but its extremely important. I think other sdn'ers can shed some light on it...
Anyways, I know how you feel. I freaked out during my PAT section, and it killed me. Even though I got a (20) there was a period of time where I just was like OMG OMG OMG and then your mind just goes blank and you either A)Crash and burn or B) Calm down and recover.
For the people looking for tips: just know that you will probably freak out. But it's ok CALM down. It will save your life. Don't tihnk about WHAT IF. JUST calm down and recover. Period.