I used to obsess over what other people thought of me and would spend so much of my energy trying to please them, I had no idea how to be myself. My therapist had me write this down, and I would read it every morning as part of my daily meditation:
"What other people think or feel about me is none of my business, unless I have wronged them, and if so, I need to make amends if doing so doesn’t result in further harm.
And when I’m working my boundaries, which implies I know what they are and honor them, what other people think of me is more about them and their history than it is about me."
As others have noted, all that hostility is his history, not yours. We can't control how other people behave; all we can control is our reaction to others' behavior.