When to TTC after losing your child?

My husband and I welcomed our sweet baby boy in June, and to our complete shock he was born with a rare defect which he passed from in September. Our hearts are crushed, but my husband and I were so ready to have a baby. I have a five year old daughter already. We are really wanting to have a baby this year (2016), seeing as how jobs/school and such will not allow us to have one in the years 2017-2019.. I'm just wondering if any of you who have endured my same pain have gotten pregnant 6-8 months after giving birth. I'm extremely nervous for a numerous amount of reasons.