..or maybe he was wounded doing something heroic but the only way they could save him was by putting his brain into a female body? So when he wakes up he's very disorientated but then starts thinking 'hey - I got tits. Lets try for multiple orgasms'. Soon though he is discharged to a fitting heroes welcome: pictures in the press, promise of a free wardrobe and make over by Vogue.
Of course his married life became difficult: lots of questions from the press, from people on the street. You know the sort "Hey buddy, I envy you! We all love lesbian porn, now you get to do it for real" or "Hey, if you and your missus, well, y'know, if you need a man in your life, then look now further - I'd be happy to help out". That constant pressure on both his wife and him proved a step too much: his marriage had been a little shakey and soon he'd moved out and his wife filed for divorce - who could blame her after all? Of course he couldn't move in with friends or family, because he didn't want to put them in a difficult situation: even after 8 months, the press were always hanging around.
Lets make him a cop - that would explain the hero injury. So he goes back to work: it's the job he loves and there are laws to give him equality rights. At first his co-workers listen to his opinions and complaints, like maybe his body-armour is too heavy or the recoil on his gun means he can't shoot as well as he used to. One day, one of the guys gets in an argument with him that ends up with "You know since you became a woman, you've started to goddam well think and act like one too." and whilst his old buddies jumped to his defense, he starts to find he was becoming ignored in discussions, despite his experience in the job and people stopped asking for his advice.
On one such day his period was due - he'd had them before but he was never quite sure how he'd be, which irritated him, because life was a damned site more predictable before. Someone in the briefing room made a wise-crack about a rape investigation and he jumped to his feet and banged on the table. Everyone looked his way but as he looked round the quizzical faces, the guys still chewing gum, his inspector looking over the top of his glasses at him, it was all too much. Waving his hand into the air as he turned, with his face flushing red with anger but his eyes filling with unwanted tears he stormed out of the room.
He kicked the door of the ladies restroom open and pushed it shut with a shove of his butt, just in time to hide the sound of a loud sob. "Fuck it. Fuck these tears! What the fuck is happening to me?" A voice answered him, "Well, well if it isn't our resident Romeiet or is it Jumeo - I forget which. Wassup sister, guys giving you a hard time?" The woman who answered was like most of the serving women, not heartless, but used to toughing it out on the street, except this one, Mardi, was a woman he'd made a pass at a couple of years before.
"They're such a bunch of assholes, Mardi. Jesus! We've got that assault and rape case on precinct 22 and the guys are just joking about it."
"You don't like it sister? File a complaint. You got a problem with men? Get used to it."
"How can you say that Mardi? I'm a woman too - where's the sister love I used to hear all about?"
"Don't make me laugh. Ain't no woman gonna come near you when we know there's a set of guys eyes looking out at us. You think you can just jump ship with medical science and suddenly you're a woman? Sister you need to have grown up a woman, been told you're an ugly girl or a fat girl or had boys trying to look up your skirt or pull your hair. You know nothing. You're fake and a freak." Mardi pushed her aside and stormed out.
He got back off the tiles and looked at himself in the mirror. He looked like a woman but Mardi was right - those were a man's eyes looking back. His face darkened, his mind saw only black.
He took leave for the rest of the day and headed back to his one-bed apartment. He locked the door behind him as usual and poured himself a large scotch, noticing how his hand was still shaking. He drew all the curtains because he'd seen enough of the world that day and he sure as hell didn't what it to see him. He looked at the time, 11am. Maybe he had enough booze to last him the rest of the day?
He didn't know his neighbours too well: mostly he avoided people because of their interest in him. Some were good people, caring people. Some were divorced like him. Most had jobs, different hours, shift-work - just regular people in a regular neighbourhood so no one heard the muffled sound of a shot or the chair scraping as his body slumped on the floor. The police would be along in time of course and people would ask "Why? She had everything going for her."
Is this what you had in mind?