'Elvira' 's Cassandra Peterson Was 'Most Worried' About Her LGBTQ Fans' Reaction to Her Coming Out

Cassandra Peterson is living her truth after coming out this week, revealing her 19-year relationship with partner Teresa "T" Wierson.

The Elvira: Mistress of the Dark star, 70, tells PEOPLE it was "a little scary" but "very liberating and a real relief" to open up about her relationship in her new memoir, Yours Cruelly, Elvira: Memoirs of the Mistress of the Dark.

"It's been fantastic. Everybody is happy and thrilled about it," says Peterson. "I felt the strangest and most worried about my LGBTQ fans because I was thinking, 'Are they going to think I'm a big hypocrite?' And that I talk about coming out, being who you are, and then I'm hiding this gigantic secret."

She's since been met with love and praise from her loyal fans, especially in the LGBTQ community, noting that the response "without exception, has been so supportive and sweet."

"I know they're loyal and they love me, so I really shouldn't have been afraid," Peterson adds. "But that part of me, somewhere in my head said, I don't know, 'Are they going to think I'm a big lying hypocrite?'"

"It's so much nicer to just be who you are and I mean, if I can't be who I am by the age of 70, then, oh my God, I'm in big trouble, right? People keep saying, 'Why now?' And I say, 'Because if not now, when? When I'm 100?'" she muses.

Peterson's first book comes 40 years after she debuted her iconic character Elvira, the vampire bombshell with a Valley girl inflection and a flair for innuendo. After a career that included being a teenage showgirl in Las Vegas, posing for Hugh Hefner in Playboy and appearing in a 007 movie, Peterson was ready to throw in the towel at 30 years old before finding her calling as the Mistress of the Dark.

"When they say life begins at 30, they're not kidding. I mean, I think before 30 years old, you're just testing the water. And yeah, I would have told myself to certainly not give up. I think that's my mantra in life," she says. "Perseverance is the most important thing. You get knocked down, just get up again and start it over."

The Elvira's Movie Macabre host also credits Elvis Presley with helping her realize her full potential, during a fateful night she spent with the King of Rock 'n Roll in her showgirl days. After one of her shows, the late legendary musician gave her some life-changing wisdom.

"He played the piano and we sang together. He wrote all these notes for me which are in the book about spirituality, astrology, numerology. He was really, really into that and kind of opened up my mind about that and gave me the best advice anyone's ever given me," she recounts.

"And without that advice, I always say, at the time I was the youngest girl in Las Vegas history. If it wasn't for Elvis, right now I would be the oldest showgirl in Las Vegas history," Peterson explains. "Oh my God, I probably would be still a 70-year-old showgirl because I had accomplished my goal and I was in Vegas. I was a showgirl, it was the biggest deal in the world. And Elvis told me, 'You don't want to stay here. This is not a good place for a young girl. You have a nice voice. Why don't you get singing lessons and go on and do something else?' And I took his advice and I did it, but obviously it was a game changer."

With other big names like Lynda Carter, Jimi Hendrix and Frank Sinatra peppered in throughout the book, she admits that she still gets starstruck from time to time. But Peterson's most starstruck moment was meeting her iconic horror predecessor Vincent Price "It was like my childhood hero suddenly came alive right in front of my face," she raves.

"And he came to do my show, Movie Macabre, and I could barely talk or breathe," Peterson recalls. "I couldn't believe I was there with Vincent Price, and he was so, so sweet and charming and funny that he really, really put me at ease. And we became very good friends until his passing."

"But he was a giant hero for me as a child and I think everybody would probably agree, stars you idolized when you're a child are so important to you," she adds. "Somebody that you really, really looked up to or really idolized when you were a kid, meeting them is much bigger than life."

Peterson is returning to her horror hosting roots this weekend for Elvira's 40th Anniversary, Very Scary, Very Special, Special, airing Saturday at 8pm ET on Shudder. Her book Yours Cruelly, Elvira: Memoirs of the Mistress of the Dark is available now.