Hiya, Really well done for not just giving up - it is so horrible when you're worrying about whether your baby's getting enough to eat but it's such a good idea to seek as much information as possible before making a decision that is very hard to reverse.
Pumping can be really depressing - it takes ages, doesn't get much out, can make your breasts sore and worst of all convinces you you've not got enough milk. That's because babies are far far more efficient at propelling milk out with their tongues and lower jaw than the pump is at sucking it out. On top of that there's the hormone reflex - it can be really hard to fake the 'let down' reflex that really gets the milk flowing down from all the milk sacs to the areola.
If you can possibly get 'time out' to retreat to bed with your little one and let her feed as often as she wants for as long as she wants (do heed sensible advice about co-sleeping such as not using pillows and preferably using sheet and blankets rather than a duvet). Spend as much time as possible in close contact (maybe a sling or front pack?), letting her nuzzle in close to you even when she's not actually feeding. That should help super-charge your hormones and within about 24 hours your body will have responded to the extra demands she's making for milk by producing it.
Some people find that bottles, either of EBM or formula, make babies less keen on the breast because they have to work for their milk from you (which is good because it opens the tubes in their ears, which is why bottlefed babies are much more likely to get ear infections). If this seems to be the case, it's better to reintroduce a bottle later once breastfeeding's fully established - around 6-8 weeks.
All the very best with it and definitely call a helpline or find a breastfeeding support group in your area. There are a couple of really good sites you could look at too. This is the help and support page for a site run by a Breastfeeding Network Supporter and this is recommended by our local breastfeeding support group: kellymom. The NCT b'fg line is 0870 444 8708 or La Leche League is 0845 120 2918. As almost everyone on here has said, it can really help to talk things through with someone. Go well!