One time violence, should I leave?

Hi, I’m new here. I have been married for (detail removed by moderator) and always been what I would call “happily married”. (detail removed by moderator) was the first domestic violence I have ever experienced from him but it was horrific and sustained for a couple of hours and he is extremely sorry and I don’t feel in danger anymore but I really can’t erase the images from my mind and have said I want to separate. We have two kids (detail removed by moderator) and his first response to me saying I want to break up was him banging his head repeatedly on the kitchen floor and then said he will kill himself if I leave him because his whole life will be over and the kids lives will be ruined.

(detail removed by moderator) I couldn’t even speak I was shaking and crying as he has never threatened me before. When he advanced on me I screamed, (detail removed by moderator) He was screaming horrific things at us throughout and unfortunately (detail removed by moderator) I completely appreciate that I caused this with my choice to be (slightly) unfaithful but the response was insane and it lasted over 2 hours. He kept stopping, resting and then started on him again. I honestly think the only reason he stopped in the end was he was exhausted and couldn’t carry on but he admitted he was trying to kill him but has blamed the alcohol.

He feels it is ridiculous to end the marriage over one night of violence but I have recently started to question the relationship – (detail removed by moderator) but really he had been manipulating the situation since I was about (detail removed by moderator) People always said he groomed me but I loved the attention and didn’t really understand. The love was always quite one sided but he adored me and I was happy with that. He has always been a bit controlling but I am easy going and compliant so it has never felt uncomfortable. He says the violence was only because he loves me so much but I feel it is more possession and control than love, especially because the transgression was a minor physical thing, not even sex or a confession of love. I know it was wrong but it feels like a massive exaggeration and I don’t see how I can ever relax and kiss/cuddle my husband again after seeing him like that. He doesn’t understand and is begging me to reconsider and has said he will win me back and I need to just be patient. Is a one off night of violence bad enough to leave someone over? I feel sure it won’t happen again, he says he will do anything and even go tee total but I just can’t find him attractive after that, it was so horrible. I feel that even if it never happens again, once was enough but I am so unsure as our life before felt fine until now. Thanks for any advice, sorry for the long post.