_{(spoilers kind of I think?)}

_{I sided against the? BoS, and now Paladin Danse is hostile. Was there or is there someway I can stop this?}

I don't think so. If you side against any of the factions in the MQ, all members of that faction are hostile. Can't really talk to Danse or Maxson or anyone to try and smooth it out, so you've pretty much burned that bridge, so to speak.

I have a save not too far back just before taking sides, apparently there's a quest before taking sides that involves danse