I really liked how you used the title here. It's like you are stating you are alive but most poets can figure out since this is in the sad category the deeper meaning behind the title to me says you don't want to be. And the introduction was well worded because to me it gives the reader the reason why you feel the way you do. The way you wrote the first stanza is great because it introduces the sad part of the poem. You can tell you are talking about death and how you feel. You seem to be embracing the fact you will someday. This person meant so much to you that they were your whole world. The tone of this poem is depression and just that one phrase "expect I'm alive" is powerful enough to stand on its own. So I love how you made it its own line.
This person seems to just be barely holding onto their life. To me it can be explained like this: physically you are here but emotionally and mentally you are not. The story is well thought out though for you wrote from your heart and soul. No matter what hang on. It might be hard now but it is worth it. Well done.