"I'm grateful to have this behind me now," Gastineau, 50, tells PEOPLE. Her corrective plastic surgery took place Feb. 26, and was performed by Dr. Frank Ryan, best known for giving Heidi Montag her dramatic full body makeover.
In October, doctors removed non-fatal Basal Cell Carcinoma inside Gastineau's nose. The surgery, which led to the removal of part of her nostril, "left me with an ugly scar and a weird pull across my septum," she says. "I was feeling a bit like Phantom of the Opera – really ugly and disfigured."
"Everyone would look at my nose and go, 'Oh it’s not that bad,' " she says. "Well, everything is not that bad when it's on someone else."
The reality star, who also had a melanoma removed from her thigh in 2006, now goes for quarterly check-ups and diligently avoids the sun. Says her daughter and Gastineau Girls costar Brittny, 27, "My mom is my best friend and my business partner, so hearing the word 'cancer' was so scary."
The two have since designed a Shaded Sun pendant for their Tres Glam jewelry line and plan to donate partial proceeds to cancer charities. "What the piece will signify is awareness," Lisa says, "and [serve as] a reminder to check your skin."