Heslin's husband Scotty Dynamo released the sad news on his Instagram account Friday ... telling the public the budding actor had died on Tuesday, July 2nd from an "unexpected cardiac event."

Dynamo stated that the young actor was in "perfect health" and the doctors have no explanation for what happened.

According to Scotty, the couple had been in the early stages of starting a family ... having started comparing favorite baby names for their potential offspring.

Heslin also had roles on the TV show "The Influencers," as well as the film "The Holiday Proposal Plan," costarring "Fresh Prince of Bel-Air" actress Tatyana Ali.

A GoFundMe has been set up to help with funeral and medical costs, as Heslin had passed after a week-long hospital battle.

Heslin was 30 years old.