comma after 'only' [conjunction]: Only, a few years later he calls

[Huesitos18]

I'm trying to write something in english but I don't really know how to do it correctly.

He thinks that's the closest he'll ever get to being a heroine.

Only, a few years later his boss calls him to his office with a new assignment and he starts doubting it.

I don't mean it like "just a few years later" but like a "but" only I don't really want to have to use a "but". Does the comma shows that, what I'm trying to get?

 

[entangledbank]

I'd suggest 'however' with a comma if you just want to avoid 'but'. It's true that 'only' can be used to mean 'but'; but both words are usually spoken with continuous intonation, not separated off as 'however' is. It is possible to give 'but' or this 'only' its own intonation phrase, and that would be indicated in writing with a comma, but it's quite colloquial. It doesn't really belong in a written style.

 

[Fabulist]

A "he" can't be a "heroine"; she can be a heroine; he can be a hero.

Only can be used for "however" or "except" if it is followed by a comma. In speech this would be detectable by a longer break between the words "Only" and "a few years" than would be the case if there were no comma in the printed form and "Only a few years" were a phrase meaning "Merely a few years" or "Just a few years."