Advice - what should I do

[user1482872887]

My partner of 2 and a half years has been speaking with his ex, I went on his phone yesterday and discovered naughty message exchange between the two. When I told him I had seen the messages he said it was because I had made him feel unwanted sexually since the birth of our daughter 4 months ago. I will admit I have completely gone off sex since our baby has arrived via emergency c-section. I have always suffered with confidence issues in the bedroom and since our daughters arrival have not gotten naked infront of my o/h and hence do not feel sexually attractive. I am and always have been attracted to my o/h it is solely lack of confidence on my part for the lack of sex, but even still he has gotten sex at least once a week (although he has had to beg and I have remained as clothed as possible) anyway, I don't know what to do now about the messages, he has blocked and deleted his ex off everything but I don't feel like I can trust him anymore. He says he loves me and it was solely out of loneliness, he has never met up with the ex just message exchanges. Would you forgive and move on? We live together with our daughter and 3 pets so have a lot invested in each other. I really don't know what to do. Any advice much appreciated.