Hi MJ, can you go back to your GP and insist on further investigation? The only way to diagnose endometriosis is through a laparoscopy.
I had similar symptoms when I had endo, but they are just a few of many, it could be many things. Are you on the pill?
Try not to stress out (I know easier said than done!). When I was diagnosed with endo, I had no children either and my doctor told me that I had severe endo, both tubes completely blocked and wouldn't be able to conceive naturally and that IVF would be about 30% success rate. Well 6 years later I have 2 healthy children and 1 on the way - ALL 3 conceived naturally. Don't give up hope yet. Keep pestering your GP for further tests, etc. Good luck. xx