have you always been heavyset? if so you may have slow metabolism.. implement some cario asap.. at long durations with a steady rate perferably first thing in the morning to jump start it.
As for partying (sips beer) very good.
Diet seems clean... perhaps you may have another issuse at hand, have you seen a doctor about this (possile medical condition)? If not i suggest you get an appointment and tell him the same as me. You can mention the juice but he will probably try to talk you out of it.