How can I overcome insomnia
Sleep issues are often caused by stress and possibly other issues in your life, for example anger and fear. The "Piece of Mind" Pack is helpful in overcoming these issues - read the book and do the exercises. Keep practising getting to your "Peaceful Place" fast. The tape, or CD, "A Peaceful Place No. 12 - Making Sleep Easy & Useful" is another tool which may be helpful.
After learning the method of going to your Peaceful Place, you can do this during the day - particularly at any time that stress occurs. Then when you go to bed at night, you will have already have released some of your stress, so will not have a build up of stress just prior to going to sleep. You can now go to your Peaceful Place whilst in bed, then tell yourself that you're going to sleep whilst in your PP. You may need to play the tape if you start to feel too stressed to tell yourself the steps of the process of going into your Peaceful Place (especially if you haven't been able to practise during the day).
When you've mastered getting to your PP, you could use a meditation method to take you to sleep. This is described in my tape, or CD, "A Peaceful Place No. 12 – Making Sleep Easy and Useful", which you would use in bed, with the light off, ready to go to sleep.