Jail is hell for Hannah Gutierrez-Reed … the “Rust” armorer is having a tough time behind bars as she awaits sentencing for her manslaughter conviction.

Hannah’s lawyer, Jason Bowles, tells TMZ … she is having a really ​difficult time in her new digs, a New Mexico detention center.

We’re told Hannah’s family is already setting up a time to visit her … and her loved ones have been devastated by her guilty verdict for involuntary manslaughter in the accidental shooting death of Halyna Hutchins.

Hannah was found guilty Wednesday and was quickly booked into the Santa Fe County Adult Detention Facility, posing for a mug shot.

As you know … Hannah was the armorer on the “Rust” movie set when Alec Baldwin shot Halyna with a prop gun loaded with live ammunition during a scene.

Hannah’s lawyer says they will be appealing her conviction, seeking to overturn the verdict and judgment.

While Hannah was found guilty of involuntary manslaughter, she was found not guilty of evidence tampering.

Remember, Hannah’s defense blamed the accident on her being overworked by the production, and her legal team insisted Halyna’s fatal shooting wasn’t on Hannah at all.

Hannah’s attorney says the courtroom was shocked when the guilty verdict was returned … and it sounds like she’s dealing with shock of her own as she tries to adjust to life behind bars.