oh popsycal, i do feel for you - been there, done the time, got the tshirt.
dd2 was exactly like this. we went through 3 months of pure hell - her in tears, me in tears, alot of screaming and tearing of hair out on both parts.
all i can say is that i tried everything - different locations, ebm, every formula on the market, water, diluted juice, different people feeding her, breast & bottle feeding at the same time (don't ask!), starvation (which i could only hold out for 12 hours for), we had every teat/bottle/cup available at home (could do demonstrations on feeding systems as we now have all the kit!), etc. nothing worked.
eventually she went to nursery and slowly started taking a bottle from her carer. it wasn't alot at first and it was slow but we got there. i continued to bf in the morning and evening and wasn't keen on stopping bf as i at least then knew she was getting something.
once she was on bottles there was no stopping her and was happy to dual feed until i stopped bf'ing at 14m. now she will happily run around the house with a bottle firmly stuck in her mouth. she's happy with bottles and cups but really loves that bottle she battled against for months (silly girl!)
i know that it is hard/demoralising/upsetting/frustrating but they do get it in the end (god how many times did i hear that, sorry). just try to stop worrying (impossible i know) and keep at it.
cat me if you want to talk