"We were just in Sardinia for a vacation," Cox, 41, tells Life magazine in its new issue. "We got into these fights two nights in a row over stupid stuff. But I could see how relationships break up if you don't go, 'What are we doing!?' So we went to a therapist, and he broke it down for us.

"He said, "Courteney, can you see how David gets embarrassed to have any kind of public fight?" I don't scream, but I have no problem saying what I'm feeling in the moment. David's the opposite. So if I need to get something out, I have to say, 'David, can you come talk to me for a minute outside?' Had I done that, (the fights) wouldn't have gotten nearly as big."

Another key to their seven-year marriage: "We just really like each other," Cox tells Life. "He gets a kick out of me, and I get a kick out of him. We're a good balance for each other. He likes the fact that I'm so gregarious – although it can also make him very uncomfortable – and I like the fact that he is so sensitive. We're a great team."

The mom to Coco, 2, and star of the upcoming sci-fi family film Zoom, also says she's started seeing a therapist on her own.

"My friend Laura Dern sat me down and said, 'Okay, this is going to be a big year for you; here's a list of things you need to do.' One of them was to write down all the things I liked about myself. She saw that I was being too frenetic – that I wasn't enjoying life as I should. I didn't know it, but she could see it as a friend. Then she said, 'I want you to go see my therapist.' I'm a great caretaker. But one thing I'm not good at is taking care of myself. My goal for this part of my life … is to be more nurturing to myself."

As she approaches 42, Cox says she feels more confident, although she admits "aging isn't for sissies. … People who read a magazine can look at the picture and go, 'She looks great for over 40!' But guess what? That's not what I look like. Lighting is everything. When you're in your car and you look in the mirror and the sun's beaming in, you're like, 'Wow, times are getting tough.' "

And, as she recently told PEOPLE, she and Arquette are hoping for a second child. "We're not trying yet," she says. "We're revving up the engines. I'm only ready 'cause time's a-ticking. If I was 34, I'd wait another year, because I like those three-to-four-year gaps. I want Coco to be helping me with the next one. One child is hard. Two is probably harder."