"It was just really physically exhausting to the point where I was like, 'I have to draw the line' and really trust my gut and give myself some grace and recognize that I can't do everything," Moore tells ET's Denny Directo. The "In Real Life" singer canceled approximately half her tour dates in June as the third trimester of her pregnancy approached.
"We did half the tour and it was so much fun," she says, noting that her husband, brother-in-law and 1-year-old son, Gus, were all along for the ride. "It was just so magical in the sense that you're in a new city every day and [Gus] got to meet new people every day, and it was an incredible life experience that he'll never remember, but we will. I think it was a very pivotal, and will be a very pivotal, part of his young life."
Moore says she planned the tour dates in support of her new album, In Real Life, before she knew that she was expecting. Initially, she planned to power through it just as she had during her pregnancy with Gus while filming This Is Us.
"It's really different being on a film set than being on a tour bus," she notes. "It's a different kind of stamina. So I was like, 'You know what? We'll definitely check back in and do this again when I don't have a baby in my belly.'"
While Moore admits that it was a "hard decision" to step back from work, she's welcoming the downtime and embracing her role as Mama.
"I also was like, 'You know what? It's OK to take a little bit of a break.' I just worked really hard for six years and I felt like that train was just constantly going, because even though we'd have little breaks in between seasons you're still like, 'OK, well then, what comes next?' Or, 'What can I do during the downtime?' and just constantly keeping ourselves busy, which is fantastic," she says. "I feel like this is the first time in quite a few years that I’ve really like, 'Whoo, power down a little bit' and just being a mom -- which is the hardest job of all."
Moore says Gus, who will be 20 months old when he becomes a big brother, doesn't really have any idea what's in store.
"We keep trying to tell him and he'll say, 'Baby brother,' but he has no idea what that means," she says. "I feel like he's so young, that he won't really remember life before being a brother, which is kind of cool."
In putting her health first, Moore has also discovered that she suffers from dry eye disease -- a condition she wasn't initially aware even existed. She recalls feeling "constant frustration" on set, struggling with eye drops that lost their effectiveness and even having to ditch her contact lenses.
"Obviously being an actor and a performer, my eyes are a really huge part of how I do my job," she says. "This dry-eye disease was really starting to impact that, and I just thought, 'OK, this is something that I'm going to have to live with.'
"But I discovered OptiLight [by Lumenis], which is a light-based treatment for dry eyes," she continues. "It's quick, it's comfortable, it requires no downtime. I'm thrilled with the results and it's really just been a total game changer in my life."
Thankfully, Moore can get back to focusing on her family and welcoming her second baby boy this fall.