Bless you honey, I know you are miserable - Yes, I had endometriosis and I remember the terrible menstrual cramps all too well - it sound like that may be what you are experiencing. Do you ever had nosebleeds during your periods? That's pretty good tip-off that endo may be present. You should also ask your doctor whether you have interstitial cystitis - it often goes along with endo and can cause recurring bladder infections and stomsch pain.
Is there any way to get hold of your doctor to see if you can take more pain medicines? Ordinarily I would tell you to try taking ibuprofen to help with the cramps and bleeding, but since you have a kidney problem, that might not be a good idea. Try lying down for a while, then getting up and walking around a little - sometimes the alternating rest and movement helps some. A warm bath might also help - eat some calcium rich foods like yogurt if you tolerate dairy foods. An herb called valerian can help to relieve cramps - you can get it as a tea or as capsules. There just aren't many home remedies that work when your cramps are that bad - ibuprofen helps but please don't take it without checking with your doctor. I find that Vitamin B1 (thiamine) helps some - you can find this in stores that sell vitamin products - it's best to get a b-complex vitamin that includes Vitamin B1 instead of taking it by itself. Sometimes all you do is put on some music and try to distract your self from the pain. Having your mom or somebody rub your back may help some too.