It is clear that there is some sort of interaction between two characters in this poem even though only the voice of one is heard. I think that the reason why this poem works is because of what people always say when they are asked how they are. The answer is usually just 'Yeah, fine' or something to that extend. This poem has taken that idea and developed into something further.
It seems that the characters in this poem had a moment of truth one night but one of them wants to pull away and go back to being in that 'I'm fine' category. This poem shows all of these things and doesn't tell, so kudos for managing to do something that others really struggle with.
However in my opinion, I feel that the form of this poem can be different. Even though it is short, it would have more impact if there are stanzas and spaces between certain lines mainly because there is a past (before the night) what is happening now and also what could happen in the future again. I also feel that 'I am here' is the most important part of the poem. by breaking this phrase to two lines, it makes the reader pause after I am and then reading 'here' is awkward after that. But if they are on the same line, the reader will read 'I am here' in one breathe, thus the impact after reading the poem will be higher. I came to this conclusion after reading the poem aloud. That's a trick I use when editing poems I write as well.