Hello I'll make this as spoiler free as I can

 

Basically I did something that made me kill on sight to a certain faction before recruiting a companion and now they wont even talk to me, just try to kill me.

Is there ANY way to fix my reputation with them? Or if anyone from Obsidian is here could you suggest to the team that all companions don't have faction affiliation?   

Its too late to reload a save I thought that the reputation would go down on its own as I misread the tutorial tip. I really want the platinum trophy for this game but at this point Ill need to make a new playthrough.

 

Thanks

If it was crime related, I heard things should calm down if you let couple days pass (go to sleep). If you made a decision which permanently made a faction hostile, then I have no clue.