You're roommate seems to be taking the whole 'End of the world as we know it' rather poorly. You should help her out.

Drastic Times

A single bomb is all it took. There was no forewarning or signs of danger, most people didn't even know that such a weapon existed until it went off. In an instant everything within 300 miles of the bomb was annihilated, turned to ash and painted on to the earth. The blast was heard all around the world and was soon followed by earthquakes and tsunamis. Within a week a nuclear winter had enveloped the world killing billions.

Your Unconventional Roommate

You managed to make it to the safety of the subway soon after the bomb went off. After a period of chaos, order was established and a system of command was put into place. Everyone was assigned a job, room, and rations. You were assigned to room with one of the few people you recognized from before the blast, Trissa.

Trissa was someone who was popular by proxy. While she herself wasn't popular, she knew quite a few people who were and was close enough that she got invited to all the parties, games, etc. This isn't to say she wasn't attractive, just that her shy tendencies and soft-spoken nature kept her from entering the core group of popularity.

You never knew Trissa well, maybe bumped into her once or twice and shared a casual conversation about the weather. However now you are the only thing she has left to remind her of her previous life.

Drastic Times is inspired by the Metro series and this video from the Kurzgesagt – In a Nutshell Youtube channel.