vaginapagina | D&C and IUD

Next week, I'm getting a D&C for suspected polyps/fibroids. I'll also be getting an IUD put in.

What should I expect from these procedures? I'm really scared :(.
For the D&C, I hope they find fibroids, because I have extremely bad cramps/weak spells that wake me up during the night right where my uterus is located, and it travels through my legs. I know polyps don't cause pain, but fibroids can, so I'm scared I won't get an answer if it's polyps. I'm going under completely for the procedure, and am very scared about that, too. I want them to be totally honest with their findings and not miss anything. Also, how bad is the pain when you wake up? And what was your experience?

I've been told the strings hurt your partner during sex and also that they can reject with small uterus' (which I do have...), but it's supposedly worth the risk, because I have extremely heavy periods (I have a bleeding disorder, but birth control hasn't been able to control the bleeding). I'm scared of it rejecting and I'm scared of it implanting itself into my walls or something. Ahhhh :(.

Any help would be appreciated, thank you!