Three short lines carry a lot of ache. The speaker has been left by someone, and what they want most is to stay put: to wait in the exact spot where the other person walked away. The word "FOREVER" in capitals stands out, as if the wish is too big to say quietly.
The second line is the tricky one. "I wouldn't clear my existence" is open to a few readings. It might mean the speaker wouldn't erase themselves, wouldn't move on, or wouldn't tidy away the traces of their life and feelings. The opening "If only" suggests they can't actually wait forever, so the loyalty is a longing rather than a possibility. Time, or their own limits, will get in the way.
The mood is quiet, stubborn and sad. There's devotion here, but also a kind of stuckness. The speaker seems caught between wanting to hold on and knowing they may have to let go. The title, "realisations #3", hints that this is one of several moments of dawning understanding.