BIG problem with WILDING

[moogle (mognet)]

I simply can’t asleep while lying on my back, I’m drifting close to sleep back and fourth

Actually, it’s possible to WILD on your side. It’s more important to be in a comfortable position.
Quote from Meow’s SP guide

Q: Do you have to lie on your back to get into SP?
A: No, you do not have to. It is best to lie in the most comfortable position to allow your body fall asleep faster.