I am also currently in the 'might have bpd' category. I know you're not supposed to self-diagnose but I am so sure. Nearly all the criteria for BPD are problems that are having a major impact on my life and have done for a very long time. So even if not ever officially diagnosed, I relate to people on here and just reading other' posts helps me sooooo much not to feel alone.
For years I wouldn't see a doctor or anyone, I was also too scared. Scared of having to truly acknowledge that I had problems, scared to talk about things, but also scared that I wouldn't be listened to and that they would think I was a stupid kid who was just a bit down.
I tried for the first time at the the age of 18. But because I wasn't honest with them completely, they didn't take me seriously and my fear that they would just treat me like I was a silly little girl came true. I tried a couple of times after that but never ended up following anything through. This year, I decided that I was going to see it through and try, and just let them do and think whatever they wanted to. Because I've been suffering for too long and you should do the same. Because at the end of the day, nothing will get any worse, it can only get better.
I have to say, I am a person (and I don't think I'm alone in this) that finds and always has found it very difficult to believe that I will ever be able to get better, or that anyone will ever really understand or be able to help me at all. But after all this time of suffering I'm at the point where I feel, even if nothing changes in my situation, at least I have tried. I'm having monthly sessions with a counsellor and waiting to see a psychologist currently.
You said that you're scared to tell them your symptoms. What are you scared of? Because the thing is, as I said, no matter what happens it can't really get any worse. It can only get better. I know that when you are suffering with anxiety that's a lot easier said than done but really, you don't have anything to lose. I also think what salted lipstick said about writing down all your symptoms and everything you are experiencing is a really good idea. I did that when I first went to talk about bpd too. If I didn't I probably would have just chickened out again.
Good luck to you
and sorry my reply was so long winded lol