Fear of TTC

We lost our daughter May 2019 to Anencephaly. We found out at our 20 weeks ultrasound. I have an 4 year old and shes been asking if we can have a baby that comes home with us and not to heaven. I'm terrified not of it happening again but just losing another child. How do you know you are ready to try again? My husband absolutely doesnt want to try. Im only thinking of it (obviously not trying now but maybe in the fall) because my daughter was so excited to be a big sister and she deserves it. Shes been amazing since her sister died. She plays with her and talks to her all the time. I just dont know what to do. I feel like a shit mom for even typing this out.