It's actually this period that's hardest and lasts the longest. That stretch of time before you truly can say that you've let go and moved on. Nothing (short of brain surgery, and maybe hypnosis) can do the letting go and moving on for you. It's a process that could take weeks or months, or even years.
All that you can do is just live life as normally as possible, and hopefully you'll wake up one morning and realise that somewhere along the way you had let go and didn't even notice.