Re: transvaginal ultrasound & endometrial biopsy
The biopsy hurts because they are actually snipping a little tissue, which causes that excrutiating pain. I don't know of many women that have had biopsies down there that said it didn't hurt.
But the transvaginal u/s isn't that bad. I've had it a few times. They basically have you lie in stirrup position (which sucks, I know) and they thread a small catheter through your cervix into the uterus. That part, to me, is a little painful and very uncomfortable. But it's manageable. If I can handle it and I'm the biggest crybaby about everything in the universe, then I'm sure you will be ok. Once they get the catheter in there, they fill your uterus with water so they can expand it and see better whether you have fibroids or polyps. It will show up really well once they get the water in there. Then once they're done, they let the water out and you sit up and it's all good. It feels a little weird when you first stand up because some water might still come out. And make sure you wear a pad for the rest of the day, just in case you expel any more water afterwards.
The biopsy I can see why you freaked, I hate those! I've never had one that didn't hurt! But I've had close to 6 transvaginal ultrasounds and it's really not a big deal in comparison. They're not snipping off any tissue and they're not even sticking you with any needles. The catheter placement is uncomfortable and a little painful but not totally unbearable. I think you will be ok.