[Celyn]

I've not gone through the NHS for counselling, but I imagine that as said above, calling them would mean they would take some basic details (name, contact details, reasons for counselling etc). You may get put on a waiting list (anywhere between weeks to months, depending on where you are and how long the waiting list may be) but if it's through the NHS it should be free. They'll probably contact you nearer the time when and where you can have counselling and who your counsellor may be.

It's understandable to be nervous. If you don't know what to say you can just say that you were referred by your doctor for help dealing with your anger, and they should be able to take it from there.

Well done for talking to your doctor, and hope you take the next step and give the counsellors a call