Endometriosis Diagnosis

Hi ladies, have any of you been diagnosed with endometriosis? If so how did you know what you were feeling wasn’t normal? How did your dr diagnose you? I get cramps and lower backache so bad for about 24 hours that I can’t sit up straight and it’s all I can do to keep from crying. Home remedies and OTC meds don’t seem to touch the pain, but I wonder if it’s worth going through diagnosis if I just have to cope once a month. Thanks for your insight in advance!