You could speak to Night Nannies (if you google you will get the number!). They have troubleshooters who will come to your house from 9pm - 7am and get your baby in a proper sleeping routine. They will do controlled crying, so you need to be comfortable with it. But the great thing is that they have the will power and no sleep deprivation to give in!
You will probably need 3-4 nights and it is about £100 a night.