In the U.K., GPs are VERY cautious about giving out sleeping tablets, because similarly to opiate-based drugs, it has been proven that your body develops tolerance so you need more and more to achieve the same effect, and also that they are very addictive and the side effects can be horrible and as bad or worse than the original problem when you stop taking them.

Do you have a T who you can work with on the insomnia issue? It may be that if you were able to do some therapy, e.g. some CBT- type work around reducing the anxiety about not sleeping, then you could use a drug for a very short-term way to help you to break the cycle. I have done this in the past. Insomnia is often linked to anxiety, and therapy can be helpful to learn ways to reduce anxiety.