Tracy Morgan Trucker -- I Was Not Drunk or High ... I'm a Scapegoat!

The trucker who caused the fatal car crash that left Tracy Morgan in critical condition says he was not high on drugs or drunk when he slammed into the SUV ... and believes he's being skewered because a celeb was hurt in the accident.

A twitter account which appears to be Walmart trucker Kevin Roper was very active early Tuesday morning ... with a remorseful Roper saying, "I wish it was me and I can't express how horrible I feel."

Roper also denies reports he hadn't slept for 24 hours, claiming the bad press is all about finding a scapegoat, as he says, "because a famous person was involved." He wrote, "I was never charged at the scene of the accident because once again i was not guilty of any crime. Not until all the TV cameras came."

Roper seems to say he was not negligent and therefore not responsible for the crash, suggesting he was not at fault.