For CBD in the UK i highly recommend the company
https://www.hempbotanics.com/
If you have any questions or quierys they have great support, and you can go down to their shop on portobello road in London to try their products and get even more first hand knowledge from professionals.
They sell everything from gummies to vapes to CBD cannabis flower.
I recommend the brand "CBDistillary"
It's legal and it can certainly help with insomnia.
My thoughts is every chemist and supermarket should offer CBD.
Do not go to Holland and barrets what a rip off.