Endometriosis & Questions for my Glow Gals!

Maegan
Rushed to A&E last night for pelvic pain so severe, I was in the fetal position on my bathroom floor. This was after having gradually worsening pain for the last 11 days. They gave me painkillers (Co-codemol/Hydrocodone in the US) and sent me up to the gynecology ward to be seen by a gyno.
Sure enough, she thinks my endo is back. Which is awful timing considering this is our first month TTC. She mentioned here in the UK (I'm originally from the US) they won't treat endo while you're TTC. Is this really the case?
Also, for those who do have endo, do your symptoms get worse gradually before AF
And last, but not least, my nausea is extremely bad due to the cramping (both from suspected endo and AF coming today!) and the co-codemol. I've taken anti-nausea meds and regular paracetamol but nothing is helping. Any tips?!
I've honestly never had a worse period/ever felt this bad in my life.