MotherFunk, you had a horrible experience, and I am sorry about that. You are changing what you said - I can't keep up if you modify what you originally said, which was, as I quoted, "And if your baby is losing weight due to not getting enough breastmilk, surely you would agree that it is in the best interests to switch to bottle, regardless of how society views you?"
Now you are saying you meant the baby is better off on formula than nothing...as if I have somehow suggested deliberately starving a baby rather than give formula.
Your HV was wrong and misinformed, and it's an unpleasant way of shifting blame for your situation onto your stress, rather than where it almost certainly lay - on the maternity care staff. A baby who has not eaten for 5 days and who has not been spotted not eating has been badly let down by the people whose job it is to check these sorts of things. My guess is that your baby was at the breast, and you were told all was well. But in fact he was not transferring milk - he may have looked as if he was, to their uninformed eyes. I expect you felt things were not right, too, but you were told not to worry and that things would soon get better.
In fact, you were right all along. Things were not fine. You were producing milk, but your baby was not getting it. Then you hit a crisis on day 6 when it became crystal clear he was in dire straits.
It might have been that you stopped letting down milk in response to that stress - you would not cease production, though, not as early as that. But milk was not getting into your baby and of course he needed formula at that point.
I may be a bit wrong about what happened - I am joining the dots to match what usually happens when a baby has a feeding crisis like this at this time. It is always due to inadequate maternity care, whatever the details.
You and your baby were let down. Stress? My a*.