The couple dated for three years and Petsch admits the break-up was so bad, every day became a "challenge" for her.
"My mental health was at an all time low...," the Cherry Blossom depicter on The CW's fantasy series tells Flaunt magazine. "Therapy was absolutely key for me to keep sane. My best friend moved in with me and that was a huge game changer for my mental health. I found ways to be creative while staying positive and reading books."
"I read this book called Vibrate Higher Daily, and it's basically about how to radiate positivity. And I found more books to help me navigate."
It didn't help that the 26-year-old was quarantined, struggling with her identity as all her projects were put on hold.
"I had a lot of anxiety over quarantine, and I felt like without my job and without Riverdale... I didn't know what my identity was," she explains.
"I'm saying this because I don't want anyone to feel like they're alone. I'm in the same boat and I feel it, and I'm right there with them... Even though there are days where I was really struggling, just to remember three things that I was grateful for - whether that be the roof over my head, or the food in my mouth - to start and end the day with really changed my mindset (sic)."