Hayden Panettiere is revealing just how terrifying her postpartum depression battle became — admitting she spiraled so badly she needed alcohol the second she woke up just to function.

In “This Is Me: A Reckoning,” Hayden detailed her traumatic C-section that left her with a uterine infection and seven blood transfusions, before emotionally struggling to bond with daughter Kaya in the weeks after.

The actress says hearing another mom admit she also struggled to connect with her child gave her a euphoric sense of relief — one she became desperate to recreate through drinking.

Hayden admits she secretly hid Fireball bottles from ex Wladimir Klitschko and was throwing back alcohol from morning to night while her life quietly unraveled.

Even after briefly getting sober in treatment, Hayden says returning to S4 of “Nashville” triggered her anxiety all over again — and alcohol crept back into the picture.