Amitriptiline (a tricyclic antidepressant) isn't usually prescribed for insomnia (though it can be, because of some sedative effects).
Imovane/Zopiclone is a much better short-acting hypnotic with none of the side effects of amitryptiline.
But I have to agree with Ginge about cutting out the caffeine and chamomile tea - damned effective stuff.
[Note to self: Agreeing with Gingernut, must go and lie down]