I would definitely read a 'gay guy goes straight' story.
Ideally for me, it would involve fear of leaving the comfort zone, wonder at the mysterious unknown/unfamiliarity of a woman's body, a desire to know what 'regular' guys are talking about when they talk about "pussy," and the guy worrying that he's only 'going straight' due to the impact of media and social norms - bowing under the pressure of expectations and the desire to not be a 'fag' any more. He'd think about all of this and not be sure what his true motivations are - does he really want to be with a woman or is he being brainwashed? Is it just curiosity (taste-testing) or is it a complete change - I can't believe I was with men for so long? Is it women in general or one woman he falls for?
Yeah, I'd definitely read that. Sorry I can't help with the writing though, too much on my plate at the moment, plus I'm just not confident about writing from a male point of view when it comes to sex.
My name is Zelia
If your cunt is your currency, you'll only get fucked.