Standing

[Caine]

I don't know our love anymore.
It walked out the door before you
and left me standing in this room.
Every breath is our last together,
as stale as dust on the wooden floor
and our portrait, still on the dresser.

I like it for its simplicity however in my opinion it is missing impact and power. Many poets can use to simplicity to leverage more power and impact. Simple does not mean underwhelming. 

"and left me standing in this room."  Leading up to this line are two strong and straightforward statements using personification. However after the lead up we are left with you standing in the room. I think trying to have the end result be worded so as to convey the high stakes of your situation would be beneficial.

"as stale as dust on the wooden floor      The line of the dust is very poetic and has meaning. However I again think the last finishing line of the poem is underwhelming. I think adding a few more descriptive words of the portrait would indicate more to the reader the significance of its existence. 
and our portrait, still on the dresser."

On a complete side not(I'm rather slow) could u explain this line "Every breath is our last together". I'm genuinely curious but don't understand it.