Feeling Betrayed by Mental Health Professionals

I got diagnosed with borderline personality disorder by a doctor after telling my former therapist for YEARS that I had it and I know exactly the moment that triggered it. She didn’t want to diagnose me with it and treat me for it because I’m not a “horrible person”. I know it takes time to diagnose serious mental illnesses like this, but is it okay to still feel left alone and betrayed by mental health professionals by not wanting to diagnose something because they see it as “evil”? I’m so tired.