Nick Viall has been crushed on national television twice before, so it's not a surprise The Bachelor star feared rejection going into his final Rose Ceremony with Vanessa Grimaldi and Raven Gates.

In a preview clip released by ABC for The Bachelor's Season 21 finale set to air March 13, Nick breaks down into tears as he holds a beautiful Neil Lane diamond engagement ring in his hand.

"I've been falling in love with her for a very long time. I feel like sometimes I've been fighting it, and I'm not fighting it any longer," Nick says of his winning bachelorette. "I am going to ask her to marry me, and my only fear now, is what if she says no?"

Wearing a sharp black-and-white suit and tie, the emotional entrepreneur and former software salesman from Wisconsin contemplates how this journey might end for him in Finland. Nick knew going into The Bachelor process he wasn't guaranteed mutual love, or a future wife, just because he served as the star this time around.

"It didn't work out with [Andi Dorfman] and it didn't work out with [Kaitlyn Bristowe], and I'm just trying not to be afraid," Nick, 36, recalls of the two former The Bachelorette stars, who had both dumped him for other men when he was ready to propose marriage.

"Because I think for me, it would be very easy to be afraid about whether she's actually going to say yes."

Vanessa, a 29-year-old special education teacher from Montreal, Canada, and Raven, a 25-year-old clothing boutique owner from Hoxie, AR, have been frontrunners from the start of Season 21. Both women are strong, intelligent and feisty to a certain extent, which are qualities Nick has always looked for in a partner.

But only one woman can leave with Nick's final rose, and -- if she accepts his marriage proposal -- an engagement ring.

"If I leave here alone, I'll be devastated, I'll be heartbroken," Nick admits while trying to choke back his tears in the video clip. "It would have been a lot for nothing -- a lot of wasted tears and a lot of broken hearts."

Nick's season of The Bachelor wraps Monday, March 13 with a two-hour finale beginning at 8PM ET/PT, followed by the season's After the Final Rose special at 10PM ET/PT on ABC.

After his The Bachelor stint ends, Nick will be competing on Season 24 of Dancing with the Stars with pro partner Peta Murgatroyd.