sleeping problems

about once a wk i feel this anxiety about sleeping, the fear of my ex coming after me just gets to me.. I am afraid to lay down and go to sleep... I hate tht he has this power over me still...he has left me alone 4 so long, but its an irrational fear and the fact tht he is mental ill and I just can't get the images out of my head!! how could a person treat another tht they r suppose to love or say they do.... everytime I go to use the knife I still feel alittle scared still. I need more than one but It was hard enough buying 1. and sleeping with the radio feels like I am giving him power and that really pisses me off!!! when does this go away?