Jessica Campbell -- the former actress best known for her role as Tammy Metzler in "Election" -- died suddenly and unexpectedly last month ... according to her family.
Jessica passed away on December 29 in Portland, and though a full autopsy has been conducted by the Multnomah County Medical Examiner ... her family is still awaiting the results.
Her cousin, Sarah Wessling tells TMZ ... the day she died, Jessica worked a normal day seeing patients at her practice -- she was a naturopathic physician -- and returned home to visit with her mother and aunt.
Sarah says Jessica went to the bathroom but never came out, and when her aunt went to check on her ... she found her collapsed on the floor. We're told the aunt tried to revive her but couldn't, and neither could EMTs when they arrived.
The family says Jessica had been complaining of congestion and felt like she was getting a cold, but they didn't think it was COVID. The autopsy results are expected soon.
Jessica's role in "Election" alongside Reese Witherspoon, Matthew Broderick and Chris Klein -- she played his younger sister in the film -- earned her an Independent Spirit Award nomination for Best Debut Performance.
She would go on to guest-star on the popular TV series "Freaks and Geeks" and star in "The Safety of Objects" and "Junk" before leaving acting behind.
A GoFundMe page has been created her help with expenses and to provide for Jessica's 10-year-old son, Oliver. Judd Apatow -- executive producer of "Freaks and Geeks" -- donated $5,000.
The family says Jessica has been cremated and they are planning a memorial.
She was 38.
RIP