If there is someone in your life who makes you feel terrible about yourself, whose mere existence has become the bane of your life, then you should consider whether they might have narcissist personality disorder. Some warning signs for this disorder are:
A sense of entitlement. Their needs trump those of other people.
Pompous or grandiose.
A habit of speaking in a tone of voice or using facial expressions that don’t match their words.
Thrives off diminishing the achievements or qualities of others, loves to talk down and belittle.
Critical of others while being extremely sensitive to real or perceived criticism or slights.
Extremely poor boundaries, does not respect the right to privacy or belongings of others.
They make you feel like you have to tiptoe around them and walk on eggshells.