Marriage counseling

So my husband and I married when we were 19, now we’re 24 with two kids. We’ve needed marriage counseling since we had our first 3 years ago. He’s finally agreed to go after we had a huge blow out fight. But now I don’t know what to expect when we go for our first appointment. Our arguments/fights are usually just from stress. Idk what to talk about or what to ask other than help with communication. Any advice is welcome.

*The big fight we had was because he was constantly talking to and about a female he worked with. I have never gotten jealous like I did this time. But in my defense, he would literally be texting her until midnight. And she will text him randomly throughout the week and weekend to ask him to get on his PS4 so they can play fortnight (with her 8 YO son too...she has 2 ps4s in her home) a lot of the time it will just be her and him playing. He has a headset so I only hear one side of the conversations. Her husband is deployed and she talks to my husband about their marriage and issues. I thought she had a thing for my husband but he said shes just friendly 😑. He admitted that he thinks she’s hot but he says that’s it. I know it’s stupid but his comment made me really upset because I’m not even a year postpartum so I’ve really been struggling with my body.