Struggling to Get a Diagnosis for My Mental Health

I'm in the UK and I feel whenever I bring up the fact that I think I have a personality disorder like Bipolar, doctors and psychiatrists just close up and act like I said nothing or brush me off. I even had one doctor tell me that "a pretty girl like you doesn't need that kind ot diagnosis" bear in mind I have ended up in hospital after a few a manic depressive. episode one which was really bad and had self harm which needed over 20 of stitches. Its a possibility that it is because I was in CAMHS at the time as I was 17. now I'm in the horrible void between child and adult services. I'm not "bad" enough. Anyone else had this problem?