Well, "sad" might be the word (it would go well on a condolence card), "creepy" it is not, I think. What was the original photo like, where you had not applied any selective colouring? Was it too bright to transport notions of transience and death?
As to the composition: I somewhat deplore the bright and out-of-focus little flowers in the foreground. They cast those strong shadows produced by the on-camera flash onto the petals of the rose, and those shadows tend to kill any photo. On-camera flash should be avoided for most of the time, other than as fill-flash in actually quite bright situations.