JK, I hope I can help.
The telephone nos. given are well worth ringing.
Unlike curlew, I can't tell you to just drop the bottles - curlew, this is not a good idea without knowing how much formula JK's baby is having....if the baby is being fed a lot of formula, you cannot expect the body to respond instantly to increased demand, and the baby could go hungry if the bottles are just dropped.
It's true, nevertheless, that the more you feed, the more milk you will make. Breastmilk supply is driven by frequent, effective removal of milk from the breast, and swapping breastfeeds with bottle feeds makes you make less milk - just as you have found
Not eating properly will not make a difference to the milk supply, but this is a common myth, and one I am often correcting on mumsnet.....
The good news is all this can be turned round - with hard word and determination and a lot of expressing!
Expressing needs to be done at least 8 times in 24 hours . It's great your dd will still go to the breast, so you can offer the breast as often as you like, but without fighting or struggling. If she doesn't want to, leave it....you want her to enjoy the breast not associate it with conflict. Give her what you have expressed, and you will (I think) need to give formula as well for some time, but you can gradually wind down the amount you are giving her.
Cuddling her in bed and keeping her close will be good, too.
If you look up relactation on the web and in the mumsnet archives, you'll find support and info.
Good luck