L.V.
A couple of suggestions: Is your child on disability? This would not be an immediate solution but could provide some income....check out www.ssa.gov for more info on this.
Do you go to a clinic associated with a children's hospital? A hospital social worker would probably have some excellent resources. If feedings are only going to be needed for a few more months, maybe they could even get things donated. The home health provider currently providing the feedings might have an "indigent" fund that could give you feedings for free or at least reduced.
If I think of anymore, I'll post back on here. :)
Good luck!