Bryan Kohberger says prison life’s already a nightmare — claiming inmates won’t stop hurling threats and crude sexual taunts his way … and now he’s begging for a transfer.

In a handwritten note, the convicted killer pleaded with officials to get him out of Idaho Maximum Security Institution’s J-Block — just a day after being transferred there on July 29. People was first to report on the July 30 note.

Kohberger insists in the note he’s not part of any recent chaos — citing “flooding/striking” — but claims he’s getting slammed with “minute-by-minute” threats and harassment, saying he wants out of J-Block ASAP.

A few days later, he reportedly slipped a guard another note claiming inmates were screaming graphic sexual taunts at him … including, “I’ll b*** f*** you” and “The only a** we’ll be eating is Kohberger’s.”

A guard’s descrpiton of the incident reportedly confirms inmates were spewing nasty language — but the guard couldn’t say who mouthed off. Still, despite his complaints, People says prison officials decided Kohberger was “safe enough” to stick it out in J-Block … for now.