I have endometriosis and after a night of drinking i bleed, is it because of my endo or something worse?

I cannot link a bout of drinking with any vaginal bleeding. I would look to a different reason & that is not obvious from the information posted.

When you say you are bleeding I assume you mean vaginal bleeding or urinary bleeding. In either case please see a Gynecologist for a complete examination. If you are concerned about your drinking please see a Clinical Psychologist to help you with this because a night of drinking is not recommended, especially with endometriosis which is already adding stress to your system.