When I was climbing the ranks I had promoters who I had done a lot for turn on me, trainers who are trying to stay relevant throw dirt on my name, some opponents gyms even got weird when their members brought up my name.
I never once let any of it get to me. I had the usual issues to deal with on the way up like doubt, guilt, ego, family, friends etc. I think these people try to use some weaknesses against you. Anyway, these things may have felt heavy at times but strengthened me on my journey, and taught me alot.
If I could give any advice on this it would be to focus on what you CAN control (yourself). Block out the noise and believe in yourself.