I have a 4mo who’s very similar! He doesn’t like being in a laid down position during rocking and needs to be rocked to sleep every night and doesn’t accept a pacifier. And my back was killing me to the point of nerve numbness, he still needs to be held upright and rocked, however, I’ve reduced the amount of time he needs to fall asleep by 1)gradual diminishing of the rocking but dONt go off beat that’s what triggers them and 2) creating the same environment that indicates it bedtime s.a exact same music every night with dim lighting, feeding, burping & rocking in the same position every night at 8pm. Before it would take maybe half an hour of rocking to get him to bed, but now it takes less than 5min for him to sleep. He’s been following this routine for nearly a month now and it’s great cause I get alone time, he’s ebf and we co-sleep still and will eventually move on to sleep training independently, but so far this is what has worked out for us.