Demaryius Thomas says his violent car crash earlier this year scared the hell of him ... telling TMZ Sports he could have DIED after he flipped his SUV in Denver back in February.
"I could have been gone," the NFL star receiver says.
As we previously reported ... Thomas was doing 70 MPH in a 30 at around 12:20 AM on Feb. 16 when he lost control of his SUV and crashed it into a curb.
A witness says he saw Thomas' car flip several times in the air .