Which do you think it is? From what I gather (mostly just online stuff, we hardly talk about negative symptoms explicitly because I don’t really have those), negative symptoms are more of the person’s traits at baseline regardless of mood. They could be super happy or completely despondent and others would have a hard time gathering that from body language and tone and stuff whereas depression is more mood-focused and will involve experiencing primarily negative feelings and thoughts and is a shift from baseline.

I’ve been kind of all over the place but you seem to have that mood aspect in there to me. Not just appearing empty but feeling the emptiness, wanting to sleep “until things are better.” You can ask your T how they would differentiate between the two and maybe they could say “well I noticed x, y, and z,” (though I know you have relatively new people so it’ll be hard to trust their judgement but it’s worth seeing what they have to say anyway).