Thanks for the query to H.C.M. Forum.
How, one can say whether it is P M S or not ,since you haven't mentioned the age?
As far as concerned about the symptoms of nausea
, mood swings all related to tension and stress
Hyper acidity is the main disorder developed by tension & all other stomach related problems are due to Hyper acidity. As you mentioned that these symptoms aggravated by coffee & alcohol i.e.one more proof of acidity.
Tension is also responsible for mood swings , laughing , crying ,so for this in my opinion consult a psychiatrist
and get his advise.
get a home pregnancy test for confirmation .
If your age is around 45 years than may be due to P M S.