I think that the anime you are looking for is called "Bloodivores".
There were prisoners and they were brought to a warehouse. They were told they had to do something I can't recall. They were given weapons to accomplish the task when suddenly a bunch of monsters started attacking them.
The main character and his three friends are "bloodivores" (basically vampires created by a drug) who are framed for a murder, then kidnapped to a remote location where they and a whole bunch of other vampire criminals are given weapons and instructed to survive a warehouse full of monsters.
Some of the prisoners banded together to keep the monsters away. The main character went off on his own I think.
Most of the vampires congregate around one particularly powerful and charismatic vampire, but the main character, his romantic interest and a few others venture off on their own.
After the prisoners defeated the monsters and found a way out of the warehouse they discovered a dystopia. I think the main character found a school or hospital that gave him déjà vu or nostalgia which made him think he had been in the dystopian city before. I think the main character also paired with someone and they stayed in an abandoned restaurant.
Upon escaping the warehouse the characters discover that they're in an abandoned city.
Some of the stuff about the déjà vu sounds familiar as well, but I don't remember the story well enough to expand on it. I dropped the anime part way through so I don't know how it ends.
The anime ran in 2016 which is far more recent than you said, but everything else lines up very close to perfectly with what I remember.
According to Wikipedia, the anime was based on a Chinese webcomic called Time Prisoners
60 years ago, a strange case of insomnia struck the population, forcing them to stay awake for more than a full week. The victims, completely sleep deprived, all went mad. To cure this illness, a new medicine was produced, but the side effects turned the patients into vampires. Humanity went to war against this new species and triumphed, but some of the vampires managed to survive. Born from a Human and a Vampire, the main character Mi Liu, "The Child of Hope," is to represent the new hope that will connect the two species. Ringleader of a bank robbery, Mi Liu is arrested and transferred to a special prison of the National Defense Agency that monitors Vampires. Trying to break free with Anji, Mi Liu is attacked by strange monsters and he finds out that the prison location corresponds to the birthplace of Vampires, the old capital "Blue Town." Why are Vampires trapped in Blue Town? What are those strange monsters attacking them? Our heroes must fight to solve those mysteries.