Was I right for leaving him are did I make a mistake?

I have just barley left my husband of 5 years. I have been having problems with his ex. She has gotten a hold of him a year ago. So this has been going on & off for a year. At first it didn't bother me that they were talking tell I found a letter in his pocket while I was looking for my phone. I was not going to read it cause it was none of my business tell I seen " I still wont to be with you" so I read it. at first it was saying he had kids & that he was married & he hoped I loved him still( it was a joke) & she wrights back saying "yeah me to. I still wont to be with you." then he wrights back "Can you get a way for30 Min's so we can talk?" Cause they were around my best friend & her family(His mom is friends with her mom). So I called my friend(which is a guy) & asking him if my husband left? he told me no. so I ask my husband a bout the letter he said it was not his. I lost my temper & hit him in the jaw calling him a liar. he told me nothing was going on & he would stop talking to her. months p and I find out he was talking to her a day before during & after my birth day. but this time she was telling him she loved him( I found out a week after my B-day. he was realy busy that day & wonted me to look at his mail) & when was she going to see him. he wroght back saying (this one was wrought on my B-day)"I'll come & see you as soon as I can get a way from my wife long enufe. love you to"I was mad & hurt with out asking I punched him & all most broke my hand this time. he said he didnot wont to hurt her filleings so he just said it to have her leav him a lone so I told him he was just leading her on & hurting me becuse he chose her filleings over mine & it was my freaking B-day. it mad me so mad that day I wroght her telling her to stop telling him she loved him & how much she wonted to see him & every thing else(plus calling her mean names). I told him if he wonted to be friends (cuse I wonted are marrige to work) with her to get on to her. so weeks all most a mounth past I found a teaxt from her she still was saying she loved him so I told my outher friend about it cause I didn't know what to do. latter that day I went over to her place she handed me his phone(he worked wher we lived she had his phone cuse she needed to call her mom cuase she was in the hospotel & I didn't have a phone any more) saying I need to look at it. befor she gave it to me she told me that some one had called him and he didnt answer the phone she told him "that her isn't it?" he told her yes it was. she told him she was going to tell me & he had left I didnt know the number & I looked at the teaxt she was saying she loved him & what nots so I left with his phone. he came home looking for his phone I gave it to him & said if he didnot stop talking to her I was leaving he told me he would stop. this time I wrought her back saying she was geting in bettwen use & to f off it was meaner then the first letter. she teaxt him on the phone saying that she thanks she is geting in between are marrig witch p me off I told him I tought she was doing it on perpusse he said that nothing would happen in between them cause she was not going to leav her husband cause he had money. he had told me one time he went over to viset her brouther and she was there she told him that she said if were where to split up she would like to get back with him. He said he was very rude with her & saying he was not going to split up with me. But he keep talking to her she keep telling him she loved him missed him when was she going to see him. I got tired of it & I left him cause it felt like I was nobody when it came to her. did I make a mistake leaving him are did I do the right thing in leaving him?