Alec Baldwin and his wife, Hilaria, are opening up about the toll the actor's "Rust" trial took on their family ... discussing the tragedy in a first look for their new reality series.

Check it out ... Hilaria calls the death of cinematographer Halyna Hutchins the "most unthinkable tragedy" -- and confirms it's on the top of the couple's mind, even as they try to parent their 7 children.

It's clear the on-set shooting in 2021, which saw Alec charged -- and later acquitted -- for involuntary manslaughter, has had a great impact on the Baldwin family ... with AB struggling to fight back tears at one tender moment in the teaser.

He said ... "Honestly, from the bottom of my soul, I don't know where I'd be if I didn't have you and these kids."

The trailer shows just how often the famous family was being hounded amid the headline-making trial ... with the couple encouraging their children to ignore eagle-eyed photogs while going about their daily lives.

Alec is filmed stopping by a therapist's office, indicating he sought professional help to work through the trauma of the trial.

Regardless of these tough moments, Hilaria assures fans their family is as grounded as ever.

She notes ... "We've had bad moments, but we found our foundation... we're solid and we're here together."

"The Baldwins" promises to offer even more insight into their tough year when it premieres on February 23 on TLC.