Am I just letting my emotions get the better of me?

I've been married for 5 years and together a total of 7 years. Our marriage has never been perfect but we've made it work. My husband came from a very clean home. Nothing was ever out of place. I came from a home that wasn't spotless but it was livable. Just the normal mess when there are 3 kids and 2 parents who work full time. I like having everything in order but seem to not be able to put that action towards my home. This is our biggest problem because my husband knows I'm capable and just feels like I don't care. Since he works full time to support our family financially then he feels it is my job to care for our son and home. I completely agree with him, but there are some days where I don't get everything done I need to because other issues come up. The fighting really started towards the end of last year a few months after our son was born. Since then I have been working even harder to show him I care. He notices it and will commit from time to time but he just feels like this is temporary and that soon I will get tired of it all and go back to how I use to do things. So far I've been keeping everything to his standards for almost 12 months. I just don't know what to do anymore. Right now we are civil with one another. Our sex life is still good. Recently we started fighting because I noticed he kept getting texts from a female I didn't recognize. When I confronted him he said it was just a coworker and nothing more. Recently I found out she is going through issues in her marriage too. My husband says they are just friends and each others support system. I guess she was a stay at home mom too but once her kids started school she went back to work. He says she is able to give advice from a stay at home moms point of view. I want to believe that is true because I do trust my husband. However I just find it weird that he deletes all their conversations and has recently changed all his passwords. We don't keep any secrets or so I thought. He knows all my logins and passwords. Am I just letting my emotions get the better of me? Any advice would be greatly appreciated. Thank you!