If it helps...
A diagnosis is not an identity. The label applies to a collection of symptoms, not a person.
No one who is diagnosed with cancer is called cancer, or for other physical ailments, they are not called a broken bone, or an alopecian, or a muscle spasm, or an AIDS.
People who work in mental health have a tendency to call people by the diagnostic label: bipolar, borderline, schizophrenic, etc. When I worked in the mental health field (I was not a clinician), as well as when I dealt with mental health practitioners for my own treatment, I reminded them to use person-first language whether they were speaking of me or of others: a person with bipolar, a person with borderline, a person with schizophrenia, etc.
Many diagnoses, especially bipolar and borderline, have criteria that make it difficult for that person to have satisfying and healthy relationships with others, and when those criteria "become" the person by calling them the label, they are treated as less than and as a problem by practitioners, by friends and families, and even by themselves toward themselves. The symptoms can be problems, but not always, and you are not a problem for having them. Mental health practitioners are there to serve you and help you live the best life you can, you are not there to serve and satisfy them.
I hope this gives you a little power in dealing with the label, but if nothing I said was of benefit, just toss it.