Ashley accepted the construction manager's proposal in Fiji on the season finale of the ABC show on Monday night, choosing him over Ben Flajnik.
Speaking on After The Final Rose, dental student Ashley said that being around JP made her "feel complete" and "brought a sense of calmness" to her.
"He has been there for me," she told Chris Harrison. "When I have low moments he is the one picking me up. We're a team, we're always on each other's side. There is so much about our relationship that makes me believe this is it for me. It's not just him, it's us and what we have together. It's the strongest relationship I have ever had."
JP said: "When I'm with her nothing else matters. I'm so in love with this girl. She's the best thing that ever happened to me."
The couple revealed that they have discussed a wedding but don't want to "set anything in stone" until they are more settled. Ashley said that she will be finished with dental school in around a month and is planning to then move in with JP in New York.
"We just want a humble, quiet life," she told Chris, adding that she feels the pair have been through the "hardest part" of their relationship already.
JP added that being separated from Ashley while the show was airing had been one of the hardest parts to handle: "It's not like anything I've ever experienced before in my life... All you want to do is tell your friends, be in public with the one you love, and you have to keep it a secret. I've been living a double life for months!"
Ashley's sister Chrystie was also at the Men Tell All taping and took the opportunity to clear the air with JP following what happened when she met him during the finale. She told Chris she was just being protective and wanted to make sure Ashley wasn't "caught up in the process", rather than having an issue with JP.
"I feel like the biggest jerk ever and I can't apologise enough," she said. "Watching the season it's clear to me that [JP] is the one. Shame on me for being so quick to judge."
JP told her it was "water under the bridge" and they shared a hug.
Bachelor Pad returns to ABC next Monday at 8/7c with a special three-hour episode featuring past Bachelor and Bachelorette contestants, including three men from Ashley's season.
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