Insecurities, help (long)

Tiffany

My husband and I have been married for just over 3 years. We have a son who will be 2 on August 4th. My husband and I went through a tough time after we had our son. We were not intimate and I was unhappy (mostly with myself so it hurt us) I had noticed on our phone bill he had be talking to an old friend very often. When I brought it up, he lied, twice. Finally he admitted it to me. He said he talked to her because he was unhappy at the time. He said nothing happened and it was nothing but them being old friends. He happily blocked her number and has no contact with her what so ever. He doesn't have social media or anything. I also spoke to her. She said there was innocent flirting but she said she thought it was okay because of how long they knew each other which she said she knows is wrong. She told me they had no plans of seeing each other and no pictures were sent. She apologized to me for all of the hurt she caused which is fine. He and I are in a great place now and he always tells me he is 100% happy with me and isn't going anywhere. My issue is, I am extremely insecure now. I worry about this happening again and get jealous easy. For instance, there is a female who works in his office. From 6/29 to 7/2 there were 8 messages on our phone bill and I got upset. He said it was regarding work and papers he needed brought to a meeting. I do believe him but I am so insecure. I recently lost 30lbs so I am really working on getting back to myself but I need some help! Any feedback would be amazing.