Sadly the NHS mental health resources are woefully inadaquate (not helped by the fact we have a health secretary who doesn't even understand what depression is)
However, I have a friend who contacted her GP about anxiety and was referred to counselling services pretty quickly. I don't know if it is a postcode lottery but time limited, non-diagnostic counselling is fairly readily available where I live. Perhaps if you returned to your GP and requested a referral to a counselling clinic?