You could express and feed her ebm for a couple of feeds a day, so that you can feel more confident about her intake? That way you can go back to offering from the breast once you are happy she is getting enough, and feel more confident?
It does take a while to settle in - and can be desperately hard to start with.
Basic stuff, has she been checked for tongue tie, thrush? Some women with v large breasts have to express a little before the feed, to enable a better latch? (Is this what they mean by 'shallow latch?)
If you are on the verge of giving up, why not offer an evening formula feed (get dh to do it) and you can express (or get an early night, and then express when you might have more milk). Do keep pumping to try and build your supply if you are going to do this. That way your options are open.
Tinies often fall asleep at the breast. It's common to have to wake them up several times during a feed - there are all sorts of methods - stripping off, flannels, blowing - it's a very common thing.
Most of all congratulations on the birth of your dd! It's so normal to be overwhelmed at this point - do try and carry on, but most of all, as long as you keep pumping, even a few bottles whilst you get your confidence together is fine. It's better if you don't, but ultimately, there is no 'failure'. There really isn't.
Dd1 fed like a dream. Ds1 was a slow starter, and then fed every two hours for ten months. Dd2 couldn't bf. (I expressed for 6 weeks then went onto formula)
In two years, no one will know or care how you fed her when she was a newborn. Don't put additional pressure on yourself xxxx
I think you are doing brilliantly. The first few weeks feel like you sit and feed All The Time. Just relax. It's supposed to be like that - you are both learning. X