I Found My Own DNA Inside a Thousand-Year-Old Female Corpse

Trying to Find a Book: Has Anyone Read This One? Even the Streamer Is Starting to Doubt Themself

The general plot is that the protagonist lives with their older sister. After coming home from work, they find their sister asleep and seemingly not breathing. Strange things start happening. They run to a friend's house, only to find that something is wrong with the friend too. Then they run into an old classmate. Eventually, the sister goes missing, and they discover a burial chamber beneath her home.