We've had problems with sleep for 4 months ? Girls, please share your …

We've had problems with sleep for 4 months ? Girls, please share your experience ?? How do you put a child to sleep without rocking them in arms for 15-20 minutes, while they cry and want to sleep? During the day they sleep max. 30 minutes, I try to extend it but it doesn't work.? They ask for breastfeed 5-6 times at night. I have a hard lack of sleep. The baby doesn't let me sleep normally during the day or night. I'm exhausted mentally and physically?. How did you solve this problem with sleep? Thank you for the advice ??