"By the time I was 30, I had lived three lives," the Real Housewives of Orange County star, 33, told PEOPLE at Bravo's upfront presentation in Los Angeles. "I'd already been married and divorced, and got engaged again just to lose him to cancer."
And although Rossi is head over heels for Smiley, 37, the fear of failure is keeping the blonde beauty from tying the knot for a second time.
"When I first got married, I thought I was going to be married for life," she said. "I thought that was it and it was really hard to fail at that marriage."
For now, the reality star is "happy and content" enjoying her relationship with Smiley as it is now.
"Spiritually, emotionally, mentally and physically, [Slade and I] connect on every level," she said. "He supports me, loves me and is so unselfish. I just feel like the luckiest girl in the world."
Watch a clip of Sunday's episode of The Real Housewives of Orange County below: