Sleeping tablets

I've been having trouble sleeping for quite a while and started taking Nytol tablets - which were a great help. The leaflet that comes with them states that they may become less effective if taken continuously, so I went to my GP, hoping to get prescribed sleeping tablets. She was very reluctant to do this and suggested I continue with the Nytol.
I wonder whether her reluctance was because there was a possibility that I could have a bad hypo at night and, because of the sleeping tablets she had prescribed, sleep through it - with dire consequences.

Has anybody else had similar problems?