A Cool Idea
The start of the story seems to have a very confused perspective that’s a little hard to follow. First, it sounds like actions in a script, then internal monologue, and then 1st person. This could be made a lot clearer with formatting. Use italics for internal thoughts, maybe bold italics for the scene-setting part?
Read the story now
The grammar mistakes are mostly small ones ("it's" instead of "its" and such).
There’s also a lot of fragmented sentences in the beginning. They can work in your favor for pacing, but there’s just too many here. It makes everything feel very… stiff.
The quality of the writing REALLY picks up at, “The white light”.
I like that he takes a pocket knife and then feels like he’s being stabbed by the air.
I find it weird he doesn’t initially know who he is or what he looks like, but he does know that he’s “not the type to hitchhike”.
You should probably find an alternate word for “desk” or just avoid saying it 4 times in the course of 7 sentences.
The main character seems to have no reaction to the old man telling him the other people tend to leave bloody messes.
You need to cut down on your use of "um".... by a lot.
The imagery of the room is really well done.
Then I didn't have notes after that because I was trapped in the story. It had a really strong ending and was really well done. But if this wasn't for a review, I probably would have stopped reading much earlier on, which is sad because the ending made it all worth it. I'd work on your openings and starting off with more energy or something to hook in the reader.