As soon as you realize this, you're hit by all of the sensations that your moment of panic had been witholding. It's new and different from all directions, your focus races between all of your senses, as your mind tries to get it's bearings.
You can definitely feel. Your shape is completely different, but you can tell that you have an "inside" and an "outside". On the inside you feel warm, and slick. You try to figue out how far "in" you go, but the feelings get fuzzy further in, so it's a little hard to tell. Shifting your attention to the outside, you realize that the woman you're a part of is sititng, since you're facing downward and you feel pressure from above. She makes a minor adjustment to her seating position, and you're struck by the incredible sensitivity of your skin as you feel individual hairs getting slightly tugged, rolled, and dragged across your surface. The hair seems to be all over you, so you suppose that this particular woman doesn't shave. All throughout you feel a pleasant buzzing feeling, and now and again there's a large bump, during which you're quickly pressed harder into whatever chair the woman is sitting on, sent up into the air, and then forced back into the chair again. This feeling is familiar to you, she must be riding the bus! You can feel her pulse passing through you, it seems relaxed.
Feeling your new body to be pretty well mapped out, you focus on another one of the senses competing for your attention. You can taste with... all of you. You've gone down on girls before, so you're familiar with the taste, but you've never experienced it like this before. All inside you, you can taste a vague watery saltiness, and this particular woman actually tastes slightly sweet. Across your surface, you taste mostly salty, sweaty bare skin, together with the small amount of fluid that's accumulated just inside your opening. There is a hint of soap and the smell of conditioner too, the woman must have showered recently.
Besides the soap, you can smell your own sweat, and juice. You're fairly clean, but as a crevice between someone's legs, pressed inside tight pants and panties, you suppose that perfect freshness doesn't last long.
You can't see, and you're not sure if this is because you're not equipped with a sense of sight, or because the pair of pants you're in is blocking the view. Either way, seeing as you're snugly cupped in a warm space, you don't mind the dark so much. It's actually pretty cozy.
You don't hear very much, the sounds from the outside world are getting muffled by the thighs pressing over you. You can hear small gurgles in the gut above you, the faint rush of blood through you, a heartbeat, and breathing noises. It sounds a lot like you've got an ear pressed up against someone's stomach.
The wish went better than you could have imagined, being a vagina feels amazing so far. The thought that you're experiencing the life of this woman in such a close way, completely unknown to her, is thrilling.
And just as suddenly as it started, you feel like you're passing out again. There's no phyiscal fall this time, but you feel like the chair has dropped out below you, and you tumble through empty black space.
Your head snaps up, and your eyes fly open. You're back on the toilet, holding the stone.