The 60-year-old actress and television personality gave a tearful update during Monday's episode of Today following Van Halen's death in October.
Bertinelli and Van Halen split in 2001 after 20 years of marriage and finalized their divorce in 2007. On Today, Bertinelli said she's been spending a lot of time with Wolfgang "Wolfie" Van Halen, her 29-year-old son with Van Halen.
"It's been rough. Very bittersweet. We're doing okay," Bertinelli said of herself and her son. "We spent the holidays together. I'll see him later today. We've been spending a lot of time together."
"It's hard. I've gone to text [Van Halen] a few dozen times," she added. "It's like, 'Oh, no. I can't text him right now.'"
Van Halen, a founding member of the rock band Van Halen, died Oct. 6 at age 65 following a battle with cancer. Wolfgang Van Halen, who also performed with the band, confirmed his father's death on Twitter.
"I can't believe I'm having to write this, but my father, Edward Lodewijk Van Halen, has lost his long and arduous battle with cancer this morning. He was the best father I could ever ask for. Every moment I've shared with him on and off stage was a gift," he wrote.
Bertinelli also mourned Van Halen's death on social media.
"Forty years ago my life changed forever when I met you. You gave me the one true light in my life, our son, Wolfgang. Through all your challenging treatments for lung cancer, you kept your gorgeous spirit and that impish grin. I'm so grateful Wolfie and I were able to hold you in your last moments. I will see you in our next life my love," she wrote.
Bertinelli hosts the Food Network series Valerie's Home Cooking.