"GP Obstruction To Treatment"

I am fourteen years old, and for the past year and a bit I have been wanting to visit my GP without an adult present, partly because I don't have a particularly harmonious relationship with anyone in my family, and partly because my issues were with my mental health.

I booked an appointment and turned up at the surgery, only to be told by the GP that she couldn't see me without an adult present. I was thirteen at the time, and quite confused, as I had made sure before booking the appointment that I would be able to see the GP on my own.

A few months ago, I booked another appointment, but this time brought a nurse along with me. She stayed in the waiting room while I went into the exam room, where I was told that she would need to come in with me, or I wouldn't be able to see her.

I don't need clarification on whether or not I can see my GP on my own - I know that I can. But I do need to know why I have been refused medical treatment, and nearly ended up committing suicide because of it.