Seeking Affordable Private Dermatologist for Treatment Advice in London

Anyone have some advice on booking a visit to the dermatologist regarding treatment advice in the UK?

I’ve been told to go through my local GP, but they don’t even have a section on the online booking form for this problem, and after that that refer you to the Derma with up to 6 months wait time.

Anyone know any places with reasonable prices for a private booking in london.