It looks like you are hurting each other,back and forth.First he cheated in dating,you decided to go ahead and got married.He was a great husband and father,but then you met an old flame and texted in inappropriate way.Whoa...what were you thinking? You are a wife and mother of four.In my opinion you still carried anger over your husband's cheating from long ago.You both should have gone to counseling and dealt with that issue long ago ,so that going forward you can have a healthy partnership.Then your husband starts insulting and disrespecting you for your texts that happened a year ago and nothing else.You both have some unhealthy behaviours. It gets more complicated when four children are involved.Can you sit with him in a calm manner and address your recent behaviour and genuinely apologize with out mentioning his past cheating.I think your husband is angry because he thinks you are trying to get even with him.If there is any chance to save the marriage, you can try with the help of experts.