Endometriosis?

For years, I've been having inconsistent periods. Sometimes I'll skip a month or two, other times I'll have my period almost a month straight, and basically everything in between. My periods have become increasingly heavier and more painful. I've had to start taking ibuprofen like candy, going through about 6+ pills a day during my period, and even with that I can hardly function. Within the last year, I've been having pain during sex, and some points completely unbearable (but my SO is really supportive). I've been on birth control pills but they haven't helped, and I stopped taking them because my acne medicine actually makes them useless.

Recently, I found out that my maternal grandmother had endometriosis and eventually a mastectomy. Do you think there's a good possibility that endometriosis is what I have too? I'm about to make an appointment at a Gyno but I don't have a current one because I'm only 19.

Any advice or opinions are appreciated💕