I feel like I’m slowly falling out of love with my S.O

So we just had a baby 4 months ago & things have been ok for the most part. About a month ago I found him sexting one of his coworkers. Obviously I was very upset, packed up his shit and wanted him to get out. But we decided to be adults and talk it out and everything has been okay lately. I just feel a small annoyance being around him, our sex isn’t what it used to be like before the incident (at least for me) and almost everything he does is starting to irritate me. Idk what to do because I don’t want to break up, I really want to make this relationship work especially for my son.