I'm so sorry Jez, I was hopeful that with the lap and hysteo it would be easy going for now on for you.
It's hard to come to terms with having no choice but to go down the path of ivf and seeing those words on paper.
I would take it one step at a time, think financially are you able to( upfront yes it costs a lot but you do get a fair bit back from Medicare within a couple of days) that's often how we do it, we scrimp and save as much as we can and then borrow from family what we don't have and then pay them back as soon as we get money back from Medicare.
DH said the other day why don't we have any savings and I turned to him and said because of ivf... He looked at me and said...hmmmm that would be the case. So it does take a strain financially.
I wouldn't even begin thinking about when enough is enough, you have enough on your plate to digest- I think you will know in yourself when that decision has to be made.
Have you thought about Chinese medicine? I was chatting with my Chinese lady yesterday and she has some stories of women with severe endo etc, and through acupuncture and herbs has been able to help them fall pregnant & regulate their cycles.
She even believes I could fall pregnant naturally but DH doesn't believe in all the voodoo **** and believes I'm being ripped off- so he won't take the herbs for his low sperm count, he is still happy for me to go as I'm so relaxed after seeing her. She was even ringing me while she was on holidays, I feel as though we are in this together. She said yesterday she will support me through the ivf and do things to compliment whether its a stimming cycle or frozen transfer.
I was in there the other day and there were two women who had already had a baby with her and were trying for number two, don't know their histories obviously though.
Take some time out to assess and to get a grip on everything you can, but I would be upfront with FS and state you want the whole shebang medication wise to give you the best chance, so your not on this roller coaster for too long.