OP here — I genuinely didn't know the GP was a mandatory gate and lost weeks. For anyone else confused: register with a GP FIRST, even when you feel fine, because you can't get a referral from a doctor you're not registered with.
Back home I'd just book the specialist directly. Here I apparently need to see a GP first, get a referral, and there's a whole gatekeeping system I didn't understand — so I waited weeks with something that turned out to be simple. Can someone explain how the referral chain actually works, and how to speed it up when it matters?