I think you are just reading too much into this. It's tagged on Lezhin as sci-fi story so I think it's the way it's represented here
Me after reading this chapter: Nice. I am happy. This is going well.
Me after reading your comment: ...
...
...
fUCK
This actually makes sense but it makes me sad so I'm hoping it is not what you said.
If it didn't have the sci-fi tag I'd be more worried, considering the depth some of the other Lezhin BLs have gone into (Moritat for example, jesus fuck).
That should be a movie!
With him being a writer and his depression, I feel like...the whole thing may be fabricated. Like, the phone shouldn't have worked, remember? So, what if he's just imagining it all and having these fake conversations with himself. That would be sad...but it would make sense as a coping mechanism since he seems to have known before hand that the house he's in now was the other boy's.