Traumatized out of baby #4

So I just had baby number 3 (DH's first), we decided we wanted two babies together before we got married. Baby is still newborn but it was beyond the worst birth experience I've had or thought I would. Everyone is healthy and I'm beyond grateful. DH is going to be 40 this year, so we were planning to have them no more than two years apart but I'm now terrified of having another some day. I'm not sure if this makes sense. I would love baby number 4 but I just don't want to go through another horrible birth.