When I was about 16 a GP told me I had depression and GAD, I didn't go to a doctor again until last year(age 20), who thought that I had Rapid Cycling Bipolar, referred my to a psychiatrist, who after a few months diagnosed me as BPD, got into therapy a few months later and my therapist agreed with the diagnosis. She also told me she thought I had PTSD but this has never been confirmed. My psych makes me feel like a bit of a hypochondriac so I tend not to ask about further diagnoses anymore.
If I was to self-diagnose i'd probably say: BPD, APD, PTSD, EDNOS, GAD and social anxiety.