Pressure on the tailbone when WILDing

I somehow trained myself to not move when i wake up and this made me realize that i can attempt WILD like so without having to go through the relaxation phase :D however the moment i enter what i believe to be REM atonia or SP or however it is called i start getting numb etc etc heavier and kind of locked into place i also start feeling and intense pressure that is very disturbing on my tailbone even though i am WILDing lying on my stomach.Anybody else having this ? It messed up a lot of my attempts and i really want to resolve this.Thanks in advance