Is it possible to hire a night nurse for one or two or three nights? Sometimes the babies just do better with someone else. Maybe they smell their mother or somehow know that they can take advantage of her.
I have had night nurses train my little ones to sleep for most of the night (around 12 to 5 am ) by 6 weeks old. By the time she left, the baby was on a good schedule.
Plus, you'll get some badly needed rest and be able to handle the baby better by day.
Hatzlacha!