Low sodium is common complication to excessive alcohol consumption. Other usual reasons are insufficient dietary intake and excessive side effects to loop diruretica. Losartan could be the cause.

I think you should go to ER or atleast call your doctor. This is a very low sodium. Could be due to dehydration in setting of uti and diverticulitis or die to water pill in your blood pressure tablets. You need to get tests to see how is your kidney function and also blood sugar level.