Peter Parker takes over SI after everyone dies in Infinity War and raises Tony's son
A few months ago I was reading a fic where everyone died in Infinity War except for Peter Parker and the Guardians, and when Peter gets back to earth 75% of the population died. Peter makes it back to the compound just in time to find out Pepper gave birth during the war, then when she dies he takes care of her & Tony's son and takes over Stark Industries, making it Parker Industries. He creates groups and sponsors the clean-up and rebuild, and along the way Michelle joins him in the effort and helps him to raise the baby.
A few chapters in we find out Tony from another timeline survived thanks to Doc Strange, but watched the others (including Peter) die. Strange brings him to the same universe Peter is in currently, but when Tony tries to contact him Peter freaks out and thinks he's just imagining him, because apparently he'd been doing that a lot after the War. (For this universe's Peter the War was years ago, but for Tony it was much more recent.)
That was as far as I got before I lost the fic. I'm not sure if it was taken down or what, but I've looked on every fanfic site I know and I can't find it. I'm hoping you guys have seen it and can point me in the right direction. :) Also, this was written before Infinity War was released, so it's definitely AU (I'm just not sure if it would be tagged as that...)