Then you should use both hands in your pussy so it will be tighter for you. Or maybe you need to get ahold of a few guys to line up and gang fist you and we can see you on the internet
women who are flexible can self fist quite easy all to do with the size of a womens hand ( usually lot smaller with slimmer wrists than guys ), good mental training though for a fem thats unsure just how good fisting can feel , first self fist then take partners fist................