My partner was portraying himself as single on a dating forum

I found out my partner was portraying himself as single on a dating forum. He said he’d pretty much always done it though knew it was wrong. He never met these women. We tried to move on. Nearly a year later I found he had tried to ring sex lines, was just before Xmas so again tried to put it behind us. Now seen he has retweeted a pic of a woman’s clothed arse to get a dirty dm message on twitter! He say he didn’t do it that he must have caught the button. I know this is bullshit as you have to confirm to retweet. He puts how gorgeous woman look or invites them over to where we live???? He’s has promised me only a few week ago that he wouldn’t hurt me again. What I don’t understand is why. He venomously denies everything till we have ripped pieces out of each other then admits it!! I honestly am at my wits end. I’m ready to call it a day as I can’t cope with it all any more. People keep making the excuse that oh he’s a man, they are visual creatures, they all do it. It doesn’t make it right! I’m constantly unsure what he is up to, he is always on his phone and I mean always. He speaks to me like a whore sometimes and is snappy and what some would call controlling. Yet he sends beautiful texts to me . Tells me how amazing I am etc, but face to face he can be so different . Do I believe the ‘accidentally caught the retweet button’ ? My gut says not.