GB&F - I am involved with an organisation called Nursing Matters, we were originally set up to advocate for breastfed infants within the asylum system, but quickly extended our brief to all breastfed infants within the UK care system.
What happened to you (breastfeeding or no!) was atrocious, appalling and unfortunate. It is not, as someone else said, shocking. I can well believe - as presumably can anyone who has had negative contact from SS - that this SW would have had your dc removed for no other reason than she took a dislike to you.
I was in a similar(ish) position. When my ds was 7 weeks old I mentioned to my HV that I was concerned about the amount he was bf-ing. Rather than tell me that 6-7 weeks is a very common time for a growth spurt, she told me to give formula, and when I refused (he was not underweight or dehydrated, and was bouncing quite happily along the 50th centile) she attempted to have us put on the at risk register. Luckily, my GP saw that there was no case and SS discharged us, but had events gone differently he could have been removed. The same HV told me that if I was still bf-ing and co-sleeping when ds was 12 months old "SS would take an interest". Cowbag.
I reported her, but AFAIK (although she was suspended from duty) she retired soon after, so never faced consequences for her actions.