this is just an idea. When a woman is gonna have a baby often a mid wife will use perenial massage. That might be a good option for you. (fun to) Massage between the two holes and stretch the vagina opening, w/ gentle pushing downward motion, and insertion of fingers w/ side to side sweeping motion at the bottom to relax sphincter muscles. Unlike fingering it is not an in and out motion, but pushing downwards w/ a back and forth side to side motion. Pushing or pulling down (not in, but down releases the sphincter muscle, and tells the body to make more room inside) Plus it is fun. If there was burning like, then you are on the right path.