We cannot support a baby right now. Is that the explanation for why he went limp?

Please explain???? Your statement & question do not give enough info to respond. I cannot tie your finances to any issue at all. Baby went limp? Lots of possibilities on babies going limp, other symptoms?
Psychological. If you are talking about your husband going limp, yes, stress and emotional issues can cause problems with erections.
What went limp??? Your penis from depression or stress anxiety? A baby? What are you talking about?