I made the decision to side with the Institute and side against the Brotherhood of Steel, making them "permanent enemies". Then I completed the mission that required that decision and returned home to Sanctuary Hills only to find that Danse is hostile. He is an essential character, so I can't kill him. He wasn't my companion at the time, so I can't dismiss him to another settlement. I sadly don't have a backup save, so I can't change my decision. I tried leading him far away, but he keeps teleporting back each time I fast travel. I even tried building a cage around him, but he glitched out of it. 56 hours in and I have an invincible teleporting enemy destroying me and stopping my game progress.

If anyone has any crazy idea they would like to say, please let me know!

That one really svcks. Have any saves before you sided with the institute? If so, all I can suggest is going back and dismissing Danse back to the brotherhood base or something. .. Even if the save sends you back 5 or 6 hours, it's a lot better than having to restart the game.