I never told anyone about it, and during them I could not get help although part of the experience was always me trying to call out to my mom without any sound coming out. After I moved out and was living with a boyfriend at 15 I never could get any help then either as I was paralyzed while trying like crazy to wake him up although I did tell him what had happened afterward because I couldn't believe he couldn't tell I was going through that. :)
Awareness during REM atonia, before separation can be very frightening. It causes many to search for reasons... some reccount an 'abduction' scenario (an entirely different thread) and some find the 'presence' very unnerving enough to think they were being attacked by demons or being visited by a witch... it's very common... SP is the origin of the term 'nightmare'.
I found early on that the presence seems to be a sort of feedback... like holding a microphone to a speaker... one is sensing the fear of oneself sensing the fear of oneself sensing the fear.... etc.
People have witnessed me in the throws of SP... they reported I just seemed to be asleep but just breathing deeper... although from my point of view I was frantically trying to look behind me, scrambling to be noticed.
These days the SP is very subtle and I no longer hang about long enough to be bamboozled by its sensations.