I feel for you - I am having a miserable time coping with the pain, but at least I am lucky as i do not want children. I pray that all will work out well for you and hang in there- vent more if you like!
I had the exact same thing happen with the clomid! You NEED to be monitored closely on clomid - something I only learned through the infertility forum here way back when I was just getting started. My doctor just sent me packing with 3 months worth of pills and told me to "call him in 3 months if I didn't get pregnant" - UNBELIEVABLE!! With clomid they need to do a midcycle ultrasound around the time of ovulation, and if the cycle is unsuccessful, than another just before you start the clomid to check for cysts. They also absolutely MUST be doing a progesterone level blood test 7 days after you think you ovulate, to make sure the clomid worked. I had to kick and scream just for the blood test my second month on it, when I thought I O'd cuz I thought I had all the monitoring signs pointing that way, but it did NOT work that month - so who knows if it worked the first month either!?? Then I had to kick and scream the following month cuz I found out about the u/s thing. They said "we don't DO ultrasound monitoring" (in a snotty voice).... yeah, and I ended up in the ER that month with a ruptured cyst! And AGAIN two months after that during my fifth cycle on clomid with ANOTHER ruptured cyst! You NEED to make sure they are monitoring you properly on this stuff.
I'm terribly sorry about it all - I have endo too (just had my second lap in 10 months on Halloween) and in the past couple of months I've had 3 cysts, including a grapefruit sized one that I was supposed to have surgery for, but it ended up rupturing (the other two did too). BELIEVE ME, I KNOW how frustrating it can be!!! I took a TTC break to try to lose weight to help my chances TTC, and I haven't been able to exercise at all because I always had cysts and my endo pain came back with a vengence! That's why I had the second lap. I have PCOS and a history of cysts, so that's why I get so many. But the clomid can do it for anyone - regardless of whether you have PCOS, normally get cysts or not. I know it's painful, and upsetting... I'm so sorry. At this point I think you just have to wait it out and decide if you want to try again. If you try again you need to make sure they are monitoring you EVERY step of the way! Maybe they are, but my guess is if they found the cyst in the ER that they aren't doing everything.
Hang in there... and lean on us if you need to. I'm hear to listen or if you have any other questions - just ask! I have a little bit more about my history in my profile which may answer some questions for you.
good luck!
-amy