"You know what? I'm here and that makes me feel good," the "RHOBH" alum and daughter of John Mellencamp told "Nightline."

"Sometimes I am so focused on 'being strong' that I forget I am allowed to be sad, cry it out, and feel very alone," said MellencampTeddi Mellencamp is reminding her fans that sometimes it's okay to not be okay.

To document the first four months of her Stage 4 cancer journey on Instagram, Mellencamp shared a throwback photo of how she looked before she got the surgery versus how she looks