My husband is abusive and neglectful?

My husband keeps an "abuse log" for me because he claims i'm abusive to him. I never put my hands on him unless i'm fighting back to protect myself. He is very manipulative and always makes me believe that everything is my fault. He's been like this since we started dating 6 years ago. Today he came after me and started strangling me screaming in my face that he's going to kill me over and over and i had to plead with him to stop. He also came after me with a knife and held it to my back as i walked up the stairs. I left a scratch mark on his neck from trying to push him off of me when he was strangling me then he called me abusive and said the cops would take his side because he had a mark on his neck is he right? We have a 3 week old son and i hate that he raises his voice around him. My husband is very neglectful and never spends anytime with me so thats what starts most of these arguments. Instead of spending any time with me he's in his game room getting high for hours on end. I dont feel like i should have to put up with this. Am i being irrational? Is there better out there? What can i do?! He said no other guy would want me because i have a kid now. Please give me some advice.