Smash Mouth’s Steve Harwell on Deathbed, Only Days to Live

Steve Harwell is experiencing the last chapter of his life — this after battling medical complications for years — and his family is saying their goodbyes … TMZ has learned.

A manager for the Smash Mouth lead singer tells us Steve has been struggling with alcohol abuse throughout his life — and now, he’s reached the final stage of liver failure … for which he’d, up until recently, been receiving treatment at a hospital.

At this point, we’re told SH is in hospice at home … where his friends and loved ones have gathered over the past 3 days. Steve’s manager says he likely has only a week or so to live.

This news comes almost 2 years after a troubling incident involving Steve … where he appeared incredibly disoriented during a live performance, slurring his words and yelling at the audience. It was concerning at the time, and shortly thereafter … he said he was retiring.

At the time, sources close to Steve told us he’d been battling ongoing health issues — stemming from a number of diagnoses he’d received over the years, including cardiomyopathy, heart failure and Wernicke’s encephalopathy. His substance abuse was also mentioned to us back then … which we were told had contributed to his declining state.

It’s an incredibly sad development for fans of his … and for music lovers everywhere.

Smash Mouth contributed some of the biggest pop culture hits in the early 2000s — including, of course, “All Star,” “I’m a Believer” and others … some of which were featured in “Shrek.”