"They've been through hell, but somehow got through the worst of it," confides a pal, who says Spelling, 47, was "crushed" in 2013 when she learned that McDermott, 54, had cheated on her.
The OK! source says it took Spelling "years" to trust McDermott again. "But he worked hard to prove himself. Now, when he says he's going out for ice cream, she believes him."
The duo worked through their issues on Lifetime's True Tori, and now they're planning a new reality series, says the friend, "to show just how far they've come."
For one, "they've learned how to control their spending," the pal notes of the couple, who at one point racked up nearly $300,000 in credit card bills and tax liens.
Amid the family's financial woes, Spelling confessed she lacked money management skills and hoped to teach their kids how to do better than she did.
"I am not great with money, and I know a lot of people read a lot of stuff about my financial things going on," the BH90210 actress admitted in the past. "I had a business manager since I was 18 years old, so I never handled any of my money. Everything, everything, went to them, so, unfortunately, I never quite learned about money. Now raising kids of my own, I'm like, that is so important."
Spelling has also noted that growing up rich made it difficult for her to lead a simple lifestyle, as she's maintained an affinity for the finer things in life.
"Even when my tastes aren't fancy, they're still costly," she confessed in her 2013 memoir, Spelling It Like It Is.
The couple may still endure some financial issues, "but most importantly," says the friend, "they've put in the effort to save their relationship. Tori and Dean have finally found a good rhythm to live by."