RHOSLC's Mary Cosby Details Grief Journey After Son Robert Jr.'s Death

But Mary wasn't burdened by the constant reminders of her late child. Quite the opposite, in fact.

"Stuff like that just comforts me, helps me get through," she explained. "It's a blessing and I don't want to lose it. I don't want to lose me, so I try not to go to that dark place. I don't want to cry about it because it doesn't do any good."

So, instead of mourning, Mary celebrated Robert's life with a "Homegoing" memorial service that emphasized her son's lasting legacy and newfound peace.

As she recounted, "Robert Jr.'s homegoing was one of the most beautiful services I have ever been in. So many people stopped by, so many people reached out. I get messages daily, every day, at least 1,000. 'Praying for you,' 'here for you,' and I don't know how to thank them, I don't know how I could reach them, but I hope they're watching. I hope they see me and I just want to tell them thank you."

Mary's mission to remain a pillar of strength despite the unthinkable tragedy continued as her RHOSLC costars made a group visit to her house for the first time after his funeral. And in the spirit of sisterhood, the women—including Heather Gay, Angie Katsanevas, Lisa Barlow, Meredith Marks, Whitney Rose and Bronwyn Newport—put aside their feuds to support their longtime cast member.

Heather described the service as "celebratory and rapturous," adding, "Like full of energy and support."

Meanwhile, Angie reflected, "Mary gave us all permission to let go, let the light in, celebrate this beautiful young boy's life. It was really beautiful."

For Meredith's part, she applauded Mary and Robert for showcasing his battle with substance abuse on the reality series. "He helped a lot of people," she told Mary, "and that took courage to share."

Mary agreed, "I believe what we did is the right thing and to this day I believe it."

After thanking her friends for supporting her through the tragedy, Mary explained why she was so determined to overcome the grief.

"I have to move forward," she stated. "And Robert would want me to keep going. And his spirit will live within me forever. He helped me see life, you know? He was a little light."

Plus, Mary hoped to show the world that "we can overcome anything," even the loss of an only child.

"I wanted to sob, but I feel at peace," she noted. "I feel like he's not battling, he's not struggling and wanting me to help and then I couldn't. That's a type of guilt that a parent has to deal with is you can't help him. You just don't know how strong you are until you absolutely have to be."

The Real Housewives of Salt Lake City airs Wednesdays at 8 p.m. on Bravo. In the meantime, keep reading to learn more about the season seven drama.