You absolutely need to speak to a criminal defense attorney because if there was sufficient proof that this was not your paraphernalia, the drops should have been dropped in the first place, especially if you do not have a previous criminal record. Contact a private criminal defense attorney and see if there is absolutely any possibility of having the conviction reversed. Then, if that is not an option, you need to see if your state allows for expungement of criminal records in a conviction. If this was a misdemeanor and not a felony, you may have better luck but it is really usually not based on time passage but more on the underlying crime itself.