First I would suggest telephoning the national breastfeeding helpline 0300 100 0212 tomorrow morning, it will open at 9.30am.
Secondly, consider whether you have the resources to spend on a lactation consultant. Latch is most likely the problem, they are the best person to help you with this. If you haven't already, look up some advice on latch from a good website like Kellymom or La Leche League.
Overnight tonight, if your baby is waking and willing to feed, I would just breastfeed directly, and take a complete break from the pump.
Nothing terrible will happen with your baby overnight if they are alert / waking and willing to try to latch and feed. They have already had the basic bloods tests. This is not an emergency and your baby will be okay tonight.
Paediatricians are not breastfeeding experts, sadly, and are in general too obsessed with measuring milk volume (which isn't really possible and FYI a low pump volume does not mean a low supply, though inversely a high pump volume is pretty reassuring!) and are too keen to advise pumping, when they have no idea how difficult and stressful it is. DOI, I am a paediatrician myself. Replacing feeding with pumping is generally speaking, bad advice. Additional pumping on top of direct breastfeeding (particularly if you can manage overnight and early morning pumping) can help to bring up supply and get more milk into baby. You should also try to switch breasts, always offering the 2nd breast. If your baby wants to latch, latch them. If they will then additionally take a top up of expressed milk, give it. Then pump, if you can (but don't forget to rest! Pumping after every single feed is torture and unsustainable, usually). Feeding directly is always better if milk transfer is taking place (can you see / hear swallowing, do your breasts feel emptier, is your baby satisfied, even for only a short time, after feeds?). Switching to pumping only is likely to risk reducing your milk supply. Supplementing with formula risks reducing your milk supply but can be a lifesaver to overcome a short term hurdle (for example, if you are stressed beyond belief, need to rest and have an impossibly sleepy baby unwilling to latch then formula over a short period whilst you access some decent breastfeeding support is more than okay. What I would suggest is feed > top up > express, and always use EBM rather than formula if you have it).
Consider ordering some silver nipple shields to soothe/heal the nipple damage you have and some plastic nipple shields now, in case these are needed to make a difference with your baby's latch later on. A passive collection system such as Haaka or Naturebond is really cheap and you may be able to collect some extra milk as you feed your baby, saving time.
Good luck, this stage is really difficult.