I wrote them a letter and they invited me in to talk about it. That was because I had selective mutism so would shut down if I tried to talk about it, so it seemed like a good idea at the time. It's embarrassing to think that I did that, but on the whole I'm glad I did.
You can make a list of things you struggle with and how you are feeling, or things you'd like to work on, how it impacts on your daily life etc. Then you can either hand it over or read it out.
You can also self refer for NHS counselling/therapies - without seeing a GP:
https://www.nhs.uk/service-search/me...rapies-service