Tooth...some tips I picked up along the way that night help you:
To help let down try a warm compress on the breast while baby is feeding or drink a warm drink. Deep breathing helps too. Visualise the milk flowing out - sounds crazy but it works.
Nights 2-5 can be a real killer and its quite normal to feel chewed on and raw. There are further growth spurts at 7-10 days, 2 weeks and then 3, 6, 9 weeks and 3, 6, 9, 12 months. Unfortunately the first few growth spurts can all seem to merge into one and it can feel never ending but it's really not.
Are you sure your latch is just right? I'm not saying it isn't because it was perfect with DS and I still got worn to the point of cracks and bleeding! But if the latch isn't right it can make things all the more painful and difficult! Is your nipple coming out lipstick shaped or with a line across? Do you feel any rubbing pain?
I hope you have some Lansinoh nipple cream. Apply before and after ever feed and before and after you bath/shower.
Try different feeding positions to help prevent RSI on your nipples (if there is such a thing
) Rugby hold, lying down and biological nurturing are all different positions you could look up and try.
One thing my kids have taught me is never fear nor become complacent. ie. just because last night was bad dont assume tonight will be the same and, in my kids case, don't think good sleep lasts forever either!
I think it's normal to feel down and worry like you are but it will settle as your confidence grows.
Isn't it funny how when we are pregnant we wish for baby to be here so we can "get more sleep" and "worry less"...and then when baby is here we realise sleep and worry-free times are long gone anyway! Both times I was pregnant I foolishly thought having a newborn was easier than being pregnant...my newborns sure as heck aren't!
Sorry I'm rambling. Long story short hun hang in there. The first 6 weeks are a trial and can be more so of establishing BF as well but the first smiles and other rewards are just around the corner!