It's 1 of the 4 agreements (a highly underrated book for living a fulfilling life) - "Take nothing personally".

The conundrum is that your feelings, thoughts & actions are secondary products of your constructed beliefs. You can't shift any of it by pure will alone, you first have to shift your beliefs. It takes little will, effort or even evidence to adopt a new belief.

My belief that allows me to take nothing personally is that their reaction is more about them than me. 

Work on incorporating beliefs that better serve you & uncover those beliefs that are causing undesirable thoughts, actions or feelings.