Ten-Zero-Nine oleh C.M. Martens

Some things you can't take back.

All Steve wanted was to find the balls to tell the girl of his dreams how he felt.

And he finally had.
Today was that day. A day engineered with no distractions. A day for just the two of them. No roommates. No cowardice. No second-guessing that the friendship they'd built over the last year wasn't more.
Today was the day his hellish existence would move into the light.

Snatched away by four simple words, Steve's day turns dark. From one second to the next, taking his future in his hands turns to a speeding train bearing down on him.

Each day more torturous than the last, he’s forced to watch his love slumber through the whole experimental procedure. A procedure that has never worked. A procedure that turns her from his friend into subject 10-0-9.

When she wakes, when she finally comes to, the first to survive, Steve wants to take it all back. The nightmare he'd been living was nothing compared to this.