Hiya, I'm sorry that you could not get the breastfeeding support that you clearly needed. DO you have any local support groups that you can get to? IT isn't too late to start feeding your baby yourself again especially as you may have healed now. You would really need to find someone local who can sit with you and help you with position and attachment.
Well done you though for battling through the pain for as long as you did and for deciding to express
how are you expressing? BY hand or pump? There are lots of different pumps and different ones work for different people so it may be worth phoning your local childrens center as some have pumps that you can hire for free or a minimal fee.
The main ways to increase supply include expressing more often. IT works on supply and demand so each time you express you tell your body that you need more. ALso lots of skin to skin and make sure that you eIther have your baby near or something that smells of your baby or a photo to look at to encourage the emotions that get the milk flowing. SOme people say that oats and fenugreek work too.
I hope that some of this helps x