Can you stop?
Crossing the line between partying and addiction
boils down to bad consequences and the ability to stop.
If you get bad consequences and cannot cut down or stop, then you are addicted. If you are not sure, try to stop anyways and see what happens. If you are not able stop, then you know the answer. If you do stop, if you feel better (or worse) after stopping, then you should not re-start.