You're turning into a girl!
Where the burning and itching has spread you skin is soft and pale. Subcutaneous fat rounds out your features, slowly making your figure more feminine. Running your fingers over your changed skin sends shivers down your spine and causes your dick to twitch. It feels good, far better than you expected. For a moment the pain fades into the background as you feel your new soft body.
It all comes rushing back as a jolt of pain comes from your hips. Looking down, you see they're getting wider! With each jolt comes an intense wave of unbearable pain and a dull cracking sound. Your hips swell out and your waist thins out. Fat rushes to your newly expanded behind, giving you a nicely rounded ass and thick thighs. Your hands running over your thighs dislodges your thick, black leg hair leaving only creamy flesh. The effects progress downwards, and you remove your shoes and socks in time to see your feet shrinking. It occurs to you that you'll have to leave this stall sometime, and your clothes aren't going to fit.
As your hips give a final crack, the pain becomes too much and you yelp. You now have perfect legs and an ass to die for but you're distracted by the tone of your voice. Your pitch has gone up noticeably; it sounds feminine. This shouldn't be a surprise given your other changes but it rattles you none the less. Your hands move up to your throat in reaction to a burning under the skin. Your Adam's apple is gone!
It seems the burning has gone away now, your whole body is now smooth and sensitive. Your lower half is now entirely feminine except for your rather erect penis. Despite the distractions your still fully at attention. Would it be better to keep it as a vestige of your manhood, or would you rather go all the way and be able to pass fully as a woman? That's all assuming you can't turn back. You don't have long to consider all this before you start feeling pressure in your upper body.
Your bone structure shrinks rapidly, your shoulders becoming smaller, your arms thinner. Any muscle you may have had under the surface is wiped away in an instant. Your ribcage contracts, morphing your barrel chest into a more elegant shape. Looking down you could easily see yourself as a prepubescent boy, if it weren't for the womanly hips and raging boner. By now the pain has worn off and all that remains is pressure. Pressure that seems to be gathering in your chest. You know what's coming, you just hope they're not too big.
Your nipples are now puffy and sensitive and you can see the flesh behind them pushing out. As they go, the pressure turns to pleasure. Your boobs are growing and it feels incredible, and god you're just so horny. You begin to masturbate, pumping your dick at a ridiculous speed. Your other hand goes to your breasts to play with your new toys. It feels so good it almost hurts but you can't cum. You don't care anymore, your moans echo through the bathroom, your cries undeniably female. The pressure from your chest subsides, your tits now huge and sensitive. You gyrate your hips, your ass squishing against the toilet seat. Why can't you just finish already?
The pressure is building again, but this time in your groin. you're still working your dick and can feel it shrinking by the second. Soon you're rubbing furiously at your new clitoris, soaked in precum. Your balls suck in, leaving a hole where they were. you can feel them inside of you, forming your new reproductive system. Your new pussy is almost complete, the lips forming into a neat little slit. Your snatch is gushing juice, and you take the plunge. You rough and inexperienced technique isn't perfect, but it's working. Your moans reach a crescendo as you work your fingers in and out of your cunt and you finally reach release. Girl cum squirts out from between your fingers, coating your thighs and forming a puddle on the floor. Your moans die down and you're left breathing heavily in the stall, your breasts rising and falling and your heart pounding.
In the afterglow your senses seem heightened. Your breathing is like rushing wind; dripping taps like heavy rain. You hear no people, however. You expect all the men are waiting in silence for the slut masturbating in the men's toilet to come out. It was so busy in here before, there's no way that nobody heard you. Your hair didn't grow much, you realised. You can't see it now, but you expect you have some kind of short messy bob. You run a hand through your hair but bump into something, and you feel it twitch. Not against your hands, but you feel a muscle twitching. Carefully reaching back with both hands you feel a set of fuzzy ears on the top of your head. "What the fuck..." you whisper in your new girly voice.
Of course having grown animal ears isn't that much further than becoming a girl spontaneously but it just seems far more strange. you stand up and feel a strange sensation. You wobble off balance for a moment before reaching round behind you to confirm your suspicions. You have a fluffy dog tail! The reality of the situation has yet to truly settle upon you, but you still know that you have to do something. How are you going to get yourself out of this?