Endometriosis symptoms and not getting a diagnosis

The middle of 2018 my general doctor suspected I may have endometriosis and sent me to an obgyn. She did a physical examination and said I have no scarring inside that she could tell. She dismissed it. Recently I think that the endometriosis might be OUTSIDE my vagina/uterus. I still have heavy bleeding and clotting on my period as well as painful cramping, headaches, nausea etc. In addition I’ve started having painful bowel movements right before and on my period. Not constipation but pressure and stabbing pain when I sit. Same during sex. Does that make sense? Has anyone else experienced this? I’m having cramping and pains randomly and it’s affecting my marriage, sex life, and my ability to run around with my kids. I feel like no one believes me...does it really take YEARS to diagnose?