So Ik this is pretty broad for a summary (sorry!) but a while ago I read this Cherik fic set sort of during apocalypse expect that Logan wasn't a part of it and it was just Erik having a change of heart and coming back to the mansion . Except Charles tried to hide the whole drugs/no powers/not being hurt by the bullet and it was angst but cute and Hank was just a great friend. I dunno if you know what I'm looking for, I think there are a few fix it gives along these lines Any help is help 💕
Based on your summary I think the fic might have taken place in the Days of Future Past timeframe (and not during X-Men: Apocalypse)? Here are two fics that I believe fit your description :D
Every Thought in Between by SomeCoolName [Cherik, Charles/Hank, NC17}
Set after their mission in Paris: All is good now that they were able to stop Raven from killing Trask; the future is even looking better. Without anywhere else to go, Erik ends up going back to the Xavier Mansion with Charles and Hank. Tension in the house rises as old wounds reopen and the three of them are forced to confront each other’s emotions. Erik doesn’t mind, as he needs a place to stay and as long as he doesn’t say anything that will make Charles punch him in the face, they’re good. But it’s not that easy to live under the same roof as your ex. And it’s definitely not acceptable to Erik, the way Hank is looking at Charles.
If You Loved Me by frau_kali, spaceAltie[Cherik, R]
Canon divergent AU set before DoFP. Having escaped from prison, Erik returns to the mansion to find Charles at his lowest point, and is confronted with the guilt of what his actions in Cuba did to his friend, and the contempt he feels at Charles for giving up as much as he has.