What Causes Heavy Periods With Clots And Nausea While On Norcotics?

I m a 32-year-old in a take narcotics several of them for a major surgery on my shoulder I usually get my period for about 3 to 5 days I had my period for two weeks straight is very very heavy bleeding with blood clots almost looking like flesh then it stopped for a week and now I have it again bleeding very bad major migraines feeling weak no energy at all I lost about 7 pounds in the last few weeks and feel nauseated every time I drink water or eat anything I barely can drink have to try to force myself to do so also I barely urinate and if I do it kind it feels weird down there if you know what I mean