There are a couple of reasons why your defense is weak. What is your response when someone references the huge database of videogame fanart/replications on the internet or basically by anyone bored in a class in middle or high school? Levine and Lichtenstein (and warhol, while we're talking about appropriation) stole and stole but the reasons they were successful was 1. because they used items that were widely recognized and 2. because at the time it was shaky stuff to photograph a photograph or to just use comic book styles. In postmodern art, rarely (if ever) is the art the object itself. Rather, the idea is the focus. You could take a random item out of your room and put it on a pedestal and say, "So? Duchamp did readymades too!" and we'll say, "Yes, but why should we give a shit if you did it again?"

If this is actually a piece about appropriation rather than a piece that is a cathartic piece of videogame/internet fanart (notice that it exists solely on the internet for the majority of its viewers at this point), you would be at least acknowledging the amount of fanart that already exists. That would mean drawing a drawing or a deviantart forum (the forum itself). Or it could be a cathartic piece, but for it to be art and not craft (you said yourself that it's part of the fine art program), you'd have to do something like a sickening amount of repetition to bring the focus of the piece back on yourself (for example doing dozens of these and presenting them in a way that shows that the point is the catharsis). Until then it falls in line with the thousands of bits of fanart that already exists.