Unfortunately the best way to deal with the pain of a superman is just to do it over and over and over again. You can try the beginner* way to get into it (invert, handstand, slide legs down, reach one hand behind you, then you're in a superman an arm's length from the floor. If you're on a spinning pole, you can then push yourself around and play with your legs). Try adding this to routines and freedance, because the performance aspect may help distract you from the pain, and you can get into it more easily while building tolerance.
I have no idea of your relative thigh size from a picture, but I found what really helped me and my large thighs was to grip the pole about halfway down my thigh, rather than right at the top. If I try to grip at the top, my leg gets "stuck" on the pole mid-flip, and my hand ends up too low. So maybe play around with where your thighs grip. Maybe superman has a "sweet spot" just like the knee hold?
(By the way, by "beginner" I mean beginner at learning superman, not pole in general!)