Firstly thanks to Kayz for kindly posting this for me... its nice to come on to advise than posting asking for it and not having time to get back and see the responces!!
Bit of background to add to what Kayz put for me...
DD2, born 8wks prem, started breastfeeding for herself on day 9, came home on day 17 fully breastfed, was very slow to gain weight, but was gaining about 0.5-1oz a week, at around 3.5wks old she got ill and was in hospital for another 5 days, lost the weight she'd gained and was then static for a week, then she started to gain again, allbeit slowly, but the Neonatal outreach (special SCBU) nurses said it wasn't good enough and that if i didn't introduce formula she'd not get enough calories for her brain and body to develop fast enough...
So i introduced a bottle of formula very reluctantly, a week later she'd put on 140g and the nurse still wasn't happy so wanted me to add another bottle, since then my supply has almost halved daily! This morning when she had her bottle I expressed only 10mils from each side. Over the last 48hrs after each time i feed her (and her draining each side) she's starving and wanting more but gets very frustrated when i dont have a single drop left for her.
Phoned the nurses and asked to loan an electric pump, and over the day have decided that once my supply is back up i'll go back to 100% breastfeeding and just feed on demand as i was before introducing the bottle.
IMO adding the bottle has just delayed her growth even more, as she's been getting the extra calories from the formula but getting less milk from me, so its not doing any different to what just BF would. And i'm almost certain that if i'd not introduced the bottle she'd have started to gain more and more weight each week if just left to BFing!! I fed both my other 2 DC's until 12mths and didn't have a single supply problem, so IMHO i think the bottle has caused the problem and done the opposite of what they wanted!!
So after a very long post, and a read of advise i'm going to be demand feeding, and pumping after each feed aswell to increase supply, will attempt co-sleeping but will see how it goes on that front, am getting lots of skin-to-skin with her... and as soon as my supply is up to about 2oz every 3hrs from one side i'll stop the formula and just breastfeed!!
Thanks for all the advise, its good to know i'm not the only one who's had problems!!