My husband is addicted to porn & I'm beginning to hate him

I have been married for almost 2 years with an 8 mth old baby. I discovered shortly after I got married that my husband is really into pornography/masturbation. He's also registered in pornography sites but claims he's not into cyber sex. I've confronted him several times and told him how I feel about it and he promised to stop. But every now and then he still does it.
He says it makes him perform better in bed and also its easier than having sex. He also says he sometimes doesn't want to disturb me so prefers to masturbate sometimes. I can rate our sex life below average. Please what do I do because I am developing hatred in my heart for my husband and can"t stand it any longer