Occult, Esoteric, Magick, and Paranormal

I'm a large guy 6 ft 1 in and 280 LBS.

I struggle to sit criss cross for an hour because my legs get tired and my thunder thighs sorta push me off kilter and I wanna lean back.

So I've been sitting on my shins instead and this is way better for maintaining posture but I have just barely 20 minutes before my legs fall asleep and then it hurts once I get up to journal.

I don't want to use a chair or a pillow because I travel a lot and there's no guarantee I'll have those with me.

Any position suggestions? Maybe I'll look into a pillow or mat.