Non-molestation order?

Has anybody on here ever had to take out a non-molestation order against an ex? I'm currently 16+5 and my ex has been causing me hell! Harassing me, stalking me. I've got all the messages and statuses screenshotted and saved onto my phone. I've got over 120 screenshots!! Only problem is he is the father to my baby. He's a danger to myself and I'm scared he'll be a danger to my baby. He reckons he's taking me to court once baby is here to force his name down on the birth certificate. He scares me, he's ruined my life! I'm scared being in my own home, I can't leave the house without looking over my shoulder. I've even had vivid dreams about him coming to kill me! He's having a really bad effect on me. He's laid low the last couple of weeks but I'm still terrified. The police have been involved and they issued him with a harassment letter and then left it at that. He has a thing for playing with knifes and threatening to knife people. I've got screenshots of him saying he'll knife someone and also screenshots of knifes that he's brought. I've never said I'd stop him seeing the baby but he has to be clear from drugs before he visits. Can anybody advise me as to what I can do?