Juliana Primus says her worst nightmare has become a reality. Her sister went missing three weeks ago after being discharged from a Queens hospital.

“It has been turmoil,” Primus said. “It is the most painful thing that you can put a family through just because of your neglect. That is the hospital. You’re supposed to take care of people like that.”

Samantha Denise Primus — called Denise by her family — is deaf, mute and autistic. Her knowledge of sign language is limited, making it difficult for her to communicate.

“When you have somebody in my sister’s condition on the streets in the cold for three weeks,” Juliana Primus said. “It is three weeks today. We don’t know if she’s eaten. We don’t know if someone has given her water.”

Primus says her sister went missing Dec. 23 around 3:30 a.m. Samantha Denise Primus was with her family in Elmont, Long Island, located about a mile from the Queens border, when she decided to walk home to Brooklyn.

“The night came and everybody went to sleep and somewhere around 3:30 in the morning, Samantha woke up and decided she could wake up and go home,” Juliana Primus said. “And that’s where it started.”

That evening, Primus says her sister was picked up by an EMT and taken to Queens Hospital Center. That’s where Samantha Denise Primus was allegedly assessed by two different doctors, who determined she was mentally fit enough to be released.

Juliana Primus says her sister was given a list of homeless shelters and sent on her way at around 2 a.m. on Christmas Eve when temperatures dropped to single digits.

“I don’t know how they came to the conclusion that she was fine enough to be released on her own when she was admitted in the ER by the EMS and it was 1:57 a.m. when they released her out in the cold and rain,” Primus said.

Primus says she rides the subway to different parts of the city every day looking for her sister. She has also put up dozens of posters around Bedford-Stuyvesant and Williamsburg and says she will not rest until she finds her.

“I cannot sleep,” Primus said. “Every time I shut my eyes, I have nightmares about Denise. Every time I eat, I feel guilty eating because she is hungry. I’m cold putting up those fliers and my hands are red and I say, ‘She’s out there so I can take it.’”

The NYPD says she was last seen wearing a navy blue coat, pink hoodie, blue jeans and black sneakers. But Primus says her sister may have changed into a red tracksuit that she brought with her the night she went missing.

Anyone with information is asked to call the Crime Stoppers Hotline at 1-800-577-TIPS.