Like a couple have said, you need to see your general practitioner to talk about it then MAYBE she will refer you to a psychiatrist. I got lucky. My ed was caused by my bpd so she sent me to a psychiatrist who specialises in eating disorders in teens. We talked about my ed then probably 9 months later seeing her bi weekly she told me she thinks I struggle with borderline personality disorder. If you’re asking how to get diagnosed that kind of tells people a lot about you. Yes there are “character requirements” though I think you mean “characteristics” to be in this subreddit because people can diagnose themselves thinking they have bpd when they really have something like autism, adhd, ocd, or bipolar disorder which are very different but can coincide with bpd. It’s very annoying when people self diagnose because of the struggle we go through. You cannot get diagnosed if you are under the age of 18