My DLCs disappeared. Do I have to buy them again?
Viewing post in Our Life: Beginnings & Always - Step 1 DLC comments
You don't have, they can always be redownloaded from Itch for free ^^. What happened could be that your virus scanner though the files were suspicious and removed them. That's happened to a few people before. Maybe try turning that offer temporarily or seeing if you can mark the files as trustworthy.