I'm so sorry to hear about what you're going through... I do agree though that you really need to think about what you
need during this time. If your doctor has prescribed this very small amount, and is not concerned with risks to the baby, I would trust him. You have to think about how this medication could potentially help you--you don't want to not take it and be a total wreck, because that can be very bad for baby as well. Maybe if you take it, it will ease at least some of the stress and help you to better deal with it.
There are going to be risks both ways to your baby, because of this extremely unfortunate event that you're going through, but I will pray that you can feel at peace with whatever your ultimate descision is.