Tough decision

I'm 22 and a mom of 3 (all 3 are very close together, ranging from 15 months to 11 months apart). I just found out that I'm pregnant again, and was told that I need to abort this baby or I WILL die. While I was pregnant with my youngest, my uterus detached from the inside of my body which caused me to have my son really early. I'm not against abortion at all, it's just not something I want to do because I love all of my kids and I still want more. I know its medically needed, but I still feel really guilty and I haven't stopped crying since I found out. I dont know if I should take the chance and try to carry the baby, or if I should do what my doctor suggests. My kids are only 2, 1, and 5 months. I haven't told my family yet because I dont know if I'm going to chance it they are crazy against this stuff and are crazy Mormons. I don't want to go through that argument with them. I just need a little advice to help me decide what I should do.