Hi, i'm new

Well, I was just wondering if there's anyone here from the UK that has had problems with the mental health services for young people and if/how they overcame them?
I'm nearly 17 and have been in the service for about 3 years after self harm, suicide attempts, drinking, eating problems etc although i developed OCD at a very young age (4 or 5)
Basically, i've been messed about for a long time now.
i used to be under the child and family mental health unit, who were hugely unhelpful, made me do art therapy and a lot of therapies that i knew i would not benefit from.and referred me to adult services when i was 16, with a warning that they thought i was dependent on therapy (!?)
i saw a horrible man who basically told me i was lying and to come back in a few years, a couple of months ago.
Since then i made a complaint and saw a lovely woman, who listened to me and understood me and diagnosed me with BPD.
Since i'm under 18 she said she couldn't officially diagnose me but said she's 99% sure that's what i'll be diagnosed with in a years time.
So she told me i would be prescribed antipsychotics and receive DBT, but she'd have to confirm that with her 'team'.
then i was told i couldnt have the antipsychotics because i have a drinking problem, which is highly untrue - i sometimes have a shot of vodka when im stressed before college, or put whiskey in my coffee when im upset but thats largely due to the fact that i've had to learn to self-medicate or i would certainly not have made it through the last few years.
and now i'm told i cannot have DBT because i haven't officially been diagnosed.
so it seems i have been let down again.
anyone had similar experiences or know any ways to get help!?
im ruining everything i have and i need help.
i put my boyfriend through hell every day, im not going to college very often and my mind is a state.
I originally posted this on a different site but they basically abused me on there so I was hoping the people here would be more understanding :)