I also experienced a postpartum hemorrhage immediately after giving birth to my first child, except the Methergine did not work so they had to massage my uterus to try to get the blood vessels to contract. That did not work for quite some time and I had to be given 3 units of blood. My liver and kidneys began failing. I was kept in the hospital for 5 days. It took me quite some time to recover fully. I was told not to have more children, but we really didn't think I could anyway. We had done artificial insemination for this pregnancy.
Now for the happy part. Almost six years later I had an IUD that started giving me trouble so I had it taken out. We were trying to figure out what birth control to use, and one month after removing the IUD I found out I was pregnant. I was TERRIFIED. I ended up having a scheduled c-section and everything was fine. I had a complicated pregnancy, but the first pregnancy was full of complications too. The important part for your concerns is that the delivery was exactly like they wanted it to be. The reason they wanted me to have a c-section was because they didn't want my uterus to get worn out at all from delivery. My first labor was 23 hours long and very difficult. They think that may have contributed to the hemorrhaging, so they wanted this delivery to be short and sweet. Now I have two wonderful, happy boys!
You are not foolish to be worried, but at least now you know that it's possible to have a second child after a horror story of a first delivery. :)