What am I doing wrong..?

Hey guys, I'm looking for some feedback on my WILD technique as I'm not getting too far with it right now. Some background: I've had 3 WILDs before, maybe about a year ago, and I'm looking to get back into it now. I'm also light sleeper and I find it difficult to fall asleep normally.

My current understanding and routine is as follows:

WBTB about 5 hours after going to sleep (I've got the timing down so I pretty much always wake up during REM).
stand about and go to the toilet for about 5 minutes in the dark
go back to bed, lie down in my most comfortable position and just try to fall asleep (I can never fall asleep without shifting about a few times first for 20-30 minutes so I use this to get more sleepy)
shift positions every 10 minutes
from my 2nd position onwards, I start counting my breaths to use as mental anchor.
usually what happens: i do this for 3 more positions so thats like 30 minutes. Usually, towards the end of the 10 minutes on the 2nd and 3rd positions I can feel my arm, legs etc. going dead and numb, but then I know I'm supposed to get to sleep as well as the awareness thing so I shift.
at some point after I shift positions 3 times, I just lose awareness and I fall asleep (I can never remember the exact moment but I guess that's normal)

Is there anything that I should be doing differently? When I start to feel my body going numb, should I stick in the same position as long as I can or should I try and get comfortable? I'd really appreciate some help, thanks for reading through it :)