A New York man once dubbed the “worst boyfriend on the Upper East Side” was sentenced to up to eight years in prison for conning five women out of nearly $2 million through a series of romance and investment scams. Nelson Counne, 71, who also went by the names Nelson Roth and Justin Roth, pleaded guilty Tuesday to second-degree grand larceny and first-degree scheme to defraud in connection with a nearly-decade-long scam from 2012 to 2021, according to the Manhattan District Attorney’s Office. “Nelson Counne used an expertly crafted persona and elaborate web of lies to convince women to hand ov…