Breaking hearts is a tough business.

"Bachelorette" JoJo Fletcher is in tears during a preview of Monday's episode after sending someone home leads her to doubt her decision.

"What if that was a mistake?" the 25-year-old wonders. "That scares me ... I miss him already."

EXCLUSIVE: 'Bachelorette' Villain Chad Johnson Feels Misunderstood, Talks Possibility of a Spinoff Show

A source tells ET tonight's exit is "completely shocking," adding, "You can tell this guy didn't see it coming."

The waterworks are nothing new for JoJo, who admitted to ET at the "Men Tell All" taping in Los Angeles last week that being the "Bachelorette" can be very difficult for her.

EXCLUSIVE: 'The Bachelorette: Men Tell All' Special Will Include Tears, Drama and the Return of Chad Johnson!

"I am emotional," she shared. "It's hard. No one will understand it. Saying goodbye is so hard."

"You know what is funny too -- when people are like, 'I don't see any tears,' and I'm like, 'Are you kidding me?'" she added. "You can thank my makeup artist then, because she did a real good job touching it up!"

WATCH: 'The Bachelorette': JoJo Breaks Down In Tears (Again!) and Jordan's Family Reveals More Details About Aaron Rodgers

"The Bachelorette" airs Mondays on ABC.