‘I Will Be Strong Through This All’ (Exclusive)

The ‘Full House’ actor opens up exclusively to PEOPLE about his cancer diagnosis

Dave Coulier has been diagnosed with stage 3 Non-Hodgkin lymphoma.

The Full House actor, 65, tells PEOPLE exclusively that he was diagnosed in October after an upper respiratory infection caused major swelling in his lymph nodes.

As his swelling rapidly increased, with one area growing to the size of a golf ball, he says his doctor advised PET and CT scans, as well as a biopsy, which ultimately gave him life-changing news.

“Three days later, my doctors called me back and they said, ‘We wish we had better news for you, but you have non-Hodgkin’s lymphoma, and it’s called B-cell, and it’s very aggressive,'” he remembers.

“I went from, I got a little bit of a cold to having cancer and it was pretty overwhelming,” he says. “This has been a really fast rollercoaster of a journey.”

Related: James Van Der Beek’s cancer diagnosis

When Coulier learned of his diagnosis, he says he and his wife Melissa Bring – along with some of his close friends in the medical field – immediately worked together to meet his diagnosis “head-on”.

“We all put our heads together and said, ‘Okay, where are we going?’ And they had a very specific plan for how to treat this,” he says, noting that a bright spot in his diagnosis was when his bone marrow test came back negative. “At that point, my chances of being cured were gone low to 90%. So it was a great day.”

Two weeks after his diagnosis, Coulier says he immediately started chemotherapy. He shaved his head as a “preemptive strike,” and he opens up about his experience further on his podcast Rewind to full house with Marla Sokoloff.

“I started the podcast wearing a hat and I said, I’ve always been a man of many hats, but this hat has a special meaning because a few weeks ago I was diagnosed with non-Hodgkin’s lymphoma,” he says of the debut episode , where he opens up about his diagnosis. “It was really a conscious decision that I’m going to face this head-on and I want people to know that this is my life. I’m not going to try to hide anything. I’d rather talk about it and open up the discussion and inspire people.”

Throughout his cancer journey, Coulier says he chooses to maintain a positive outlook, especially for his wife and son Luc, who he reveals is expecting his first child. “I looked at how those words affected (Melissa) and I thought, you know what, I’m going to be strong through all of this, not just for me, but I’m going to be strong for her.”

As Coulier goes through this journey, he has been get inspiration from family membersmany of whom also went through cancer. “I lost my mother to breast cancer. I lost my sister Sharon for breast cancer. She was 36 years old. I lost my niece, Shannon. She was 29 years old,” he says, adding that his older sister Karen is also going through cancer with him.

“I saw what the women in my family were going through, and I thought to myself, ‘If I can be even 1/10 percent as strong as they were, I’ll be fine,'” he says.

In the midst of his treatments, he says he’s leaned on his sister Karen — and leaned on their shared sense of humor — to keep his spirits up.

“My sister was a trained nurse, so she has seen this from a different perspective than I have,” he explains. “She’s been so supportive and she’s funny. So we make jokes about it. One of my jokes is that in four short weeks I’ve gone from a virgin to a cancer. I’m a huge hockey fan. So when they said, ‘You’ve got the NHL,’ I thought, ‘I finally made it to the NHL.'”

“When I first got the news I was obviously shocked because I wasn’t expecting it and then reality set in and I found myself remarkably calm about whatever the outcome was going to be,” he says. “I don’t know how to explain it, but there was an inner peace about it all, and I think that’s part of what I’ve seen with the women in my family going through. They really instilled that in me and kind of inspired me because they were magnificent going through what they went through and I just thought, ‘I’m okay with this too.’ I’ve had an incredible life on a journey with incredible people around me and I’m fine. It certainly changes the perspective.”

Coulier has already completed the first of six chemotherapy treatments and is taking it day by day.

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“I have my good days. I have my bad days,” he says. actually yesterday with some friends here in detroit we were just skating around and shooting pucks and it was wonderful just being out there doing something that i love and just trying to stay focused on all the good things i have in my life.”

It includes preparing to become a grandfather: Coulier’s son Luc, 33, and his wife Alex are expecting a boy, due in March. “I have to teach him how to play hockey,” he says. “There’s a lot to look forward to.”

Ultimately, by sharing his own story, Coulier hopes he can inspire others to get tested early.

“Take good care of yourself because there is a lot to live for,” he advises fans. “And if that means talking to your doctors or getting a mammogram or a breast exam or colonoscopy, it can really make a big difference in your life.”