Thanks to all who replied. As a lifelong insomniac, and someone whose body is rarely without discomfort, I don't worry about not getting to sleep, as dontcallme says.
I also often don't have very much to get up for and often don't "rise" till after midday, having not got to sleep until 5 or 6 in the morning. However, that makes it difficult take all my medication at the proper sort of time and doesn't leave much of a day for whatever I want to do. I had been "getting off" a bit better before February, but for some reason this has charged recently.
I've tried all the "relaxation, listening to a story or white noise" stuff and at one time Cetirizine helped.
I just wondered whether anyone had tried the 5HTP and whether it had worked for them.