How to...put things inside?

Hi :) so this is a bit awkward but I know that if anywhere it’s safe to ask, it’s here. Recently I got my first physical from my gynecologist. She was very nice and gentle. But I’ve always been a bigger girl and that means I have puffier lips..down there. When I try to enter myself with my finger..it feels like there’s a wall?? Like it doesn’t exist and is blocked off? Even though I literally felt my doctor’s fingers up there. Help me..please?? Any tips? I can’t push anything in, either