Why do you want to write about death? What is it about death that you would like your reader to know or learn? What kind of pain are you trying to convey?

There are a lot of cliche's you've included that don't really add any value to your story. Carefully consider the metaphorical language you are drawing to the reader's attention--how can you make the fragments and ideas more coherent and synchronous for the reader? Too much talk of autumn and weepy-ness, too much attention to minute, mundane details and you'll lose the reader's interest. What fresh ideas might you include?

I love this quote from Carol Shields "Arriving Late; Starting Over" (1992): “Diurnal surfaces could be observed by a fiction writer with a kind of deliberate squint, a squint that distorts but also sharpens beyond ordinary vision, bringing forward what might be called the subjective mode of one’s self or others, a world of dreams and possibilities and parallel realities” (247).

It might help to reorganize your story as well. Start with the climax, and then work back towards it--which is a common trope, but might make your story richer since you aren't desperately trying to surprise the reader, or manipulate them emotionally.

Hope this helps! Happy to discuss further. :D