Pregnancy Fears

Hello All! I am 2 years post op gastric. I have been trying to get pregnant for the past 6 months and it finally happened. Thank you god! I am sooo scared and I wanted to talk to people who know what I am going through. I believe I am only 6 weeks prenant. I will be due on Thanksgiving Day. First of all, I went from 150 to 324 during and after my last pregnancy four years ago. Of course, I get the cancer that helped make me fat. I had thyroid cancer, gestational diabetes, bifurcated uteros, mitrovalve prolapse and polycystic ovarian syndrome. Needless to say my pregnancy was mainly in bed. I am sooooooooo scared that these bad things may happen again. But I received the greatest gift, a healthy baby boy who makes each day brighter. I never knew what love really felt like before I became a Mommy. I mean I love my husband, parents, brother, friends, but this is sooooo different. Second, over the past two months I have had major vomiting like after surgery. I have lost 7 pounds. I am 135 and 5'9" and a size 2. I don't think I can go back any further. I am having trouble eating anything. I never had this with the first pregnancy. I am soo scared the baby will do with out. Third, I have had severe constipation. I know this sounds silly but, I am afraid to lose the baby from straining. My doctor found a vitaim D deficiency so I am now on two prenatals, a B complex, 2 citracal, and 2 dry Vitamin D pills per day. I know these are causing constipation. I hope that that many vitamins won't hurt a baby. Also due to the vitamin problem should I have blood work done every month. Fourth, I have to have a hysterectomy after this pregnancy so it is my last chance to have a baby. All my female organs fell from losing so much weight so fast. My muscles didn't hold them in place. My gyne said I'll be ok to hold and deliver a baby but, this is my last hope. I am 37 and I already have been experiencing mid-life hormonal crisis issues. Sorry to rant. I know I am over anxious about this pregnancy. I just pray that God helps me through this to have a healthy beautiful baby. Any advice would be welcomed. Sandy