MissMummy no idea about the back pain, but it does sound like nerve/muscular pain rather than labour. Perhaps your pelvis is slightly out of alignment and pressing on a nerve? As for the leaking, a week before A was born, I had profuse wetness that I can only assume was excess discharge. Once my waters went with A, I had to use a towel, not a panty liner, despite them leaking slowly.
pass has P been checked for tongue tie? And also, sorry if I'm being daft, but what does she do when she can't sustain a feed? I'm not sure I'd know the difference between a sleepy newborn and one that can't feed well. Oh and finally, was it a 'proper' lactation MW or specialist that checked your latch? If not, even the best of MWs can get it wrong. If you want to persevere, I would def recommend you get yourself to a group and seek advice/support. Bfing does take over your life with a newborn, but it does get MUCH much easier.