The story starts as the Avengers' quinjet takes off from the helicarrier, headed toward the Battle of New York. The portion of the story I remember ends while Phil is still hospitalized. (Phil lives, and the Avengers know he's alive. They'll move him to the Tower when he's well enough to leave the hospital.)
In the fic, Clint, Phil, and Nick are in a polyamorous relationship. Nick uses the code phrase "Don't fuck this up" in public toward Clint, to say "I love you", in order to keep the relationship hidden.
Nick also texted "SNAFU" to Clint near the beginning of the story, which Clint read immediately after the Avengers told Clint that Phil had died. Clint knew, as soon as he read that one word text from Nick, that everything was okay and that Phil wasn't dead.
While Phil is still in the hospital recovering, and Nick is struggling to find time to spend with Clint, Clint is triggered into "episodes" of wanting to run away due to hearing old voices from his past (in his head) telling him he's worthless, etc. These episodes happen more or are stronger when he wakes up alone.
Thanks to anyone can help me find the story again.