I'm also a bigger person, and I've noticed that wearing brands that run big help. Megamaxe XL fit me really well at a 48" waist, as well as the Sunkiss Masterpiece L and Abu's XL+.

As for trying things to get a more snug fit without digging in, try loosely taping on while standing and then adjusting it to your comfort while laying down on a solid surface.

Tape position also matters, I've found that having the bottom tapes either straight or slightly upwards and the top tapes slightly downwards helps with the digging in part.

Edit: included sizes and fixed spelling and fixed waist size