Using the lines of the poem the raven, could it be proven that the story teller has actually killed his true love and the raven is her spirit come back to haunt him,

I do not think so. He is talking about the anguish that he is feeling at the memories of his lost love, Lenore, which the Raven reminds him of. He would not be feeling the same anguish of mind at loss if he had killed her, only anguish of the deed.