Stop us if you've heard this before ... Lenny Dykstra's got problems.

A grand jury in Union County, NJ just indicted the ex-MLB superstar on 3 serious crimes ... possession of cocaine, possession of meth and making terroristic threats after an alleged blowup with his Uber driver last May.

As we previously reported, Dykstra was arrested back in May after allegedly threatening his Uber driver -- who then stopped the car in front of a police station. 

Cops say they found evidence of cocaine and meth -- and took Dykstra into custody.