You might look at your husband's actions as an addiction. He is probably struggling on his own to do what he believes God wants for him, to stop fornicating. He probably developed this problem long before he met you, and still loves you and desires you, apart from the ongoing addiction he can't shake. If you can accept that he has a problem that makes him feel guilty and lowers his self esteem, you could support him by being patient and forgiving him when he falls. This is only if he is really trying to give up this addiction. His heart hurts when he hurts you, and when he grieves God's spirit of purity living in him. If you really want to blame someone, blame the producers of p 0 r n and soft p 0 r n in the media, that seduces all men from child to adult. And please remind him:
1 There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.