I’m freaking out

I live alone after moving out from my father's house. I live in a small 2 bedroom apartment along with 3 guys. Me and them have been friends since 10th grade, 2 of them sleep in one room since there's a bunk bed, the other guy sleeps in the living room, I have the other room for myself because I study construction and have equipment and clothes.

Today I was in my room since its summer vacation, I was watching a horror movie and the my friends went out to a party. I finished the movie and was going to get a snack from the cupboard that I filled with snacks when I moved in. I was going back to my room after taking a chocolate snack popular in norway (I live in norway) and when I opened the door to the room, everything wasn't there, I heard a voice from the kitchen and when I went there, my friends were home, drunk and looked at me and said "party was fun, I wish we never got kicked out because of you" to clarify, I've never been in a party, never.

I ran to my room and saw all my things gone, the room was brand new, clean and my stuff weren't there. I got confused and panicked because my PC had all my personal info and if I didn't find it, my entire life was basically gone because all passwords and personal stuff were saved there I checked the whole room and my friends were all saying "we just moved here, your stuff are probably at your aunt's house".

Now I'm checking the security cameras of the house to make sure im sane. I have lived in this apartment for 1 year, since I was 17 and never slept over somewhere else.