Maria's poem is a single line, and it hangs on a strange contradiction: the fear of losing a part of you that was never there. It is hard to be afraid of losing something you never owned, yet that is exactly the feeling the speaker puts into words.
The "you" could be a person, and the "part" could be a piece of that person the speaker hoped to reach, a closeness or a place in their life that never quite existed. The poem doesn't say, and that gap is part of its force. The speaker seems caught between hope and loss, afraid of an ending to something that never properly began.
The mood is quiet, wistful and a little aching. There's no anger, just a soft, confused sadness. The small slip in the wording, "apart" where we'd expect "a part," even adds a sense of distance, as if being apart is built into the line itself.