As a long term poor sleeper (predates chemo by decades) anxiety about getting to sleep will possibly keep you awake more than anything else. If you don't fall asleep relatively quickly, do something that may help lull you to sleep. I am not a fan of the 'getting up if you are not sleeping' school of thought, I'd be up all night. Sudoku in bed stops my mind chatter - not anxious or worried, just awake and thinking of too many things so I need something to turn me off. The old fashioned hot milk (Milo or Horlicks) can work so can some sedative teas. As far as I know valerian isn't a problem with other medication (always wise to check). I find that if I have been sleep deprived for a while, I need to take sleeping pills for two consecutive nights to break the 'I'm not going to get to sleep' cycle. I may then not take them again for a month or more, not really much risk of dependence!