I encounter this during my bb week 4. Nothing works for that week he just wont sleep well at night. Somehow the next week he resumed sleeping well at night. Hang in there!
Most likely your baby is having gassy stomach or colic problem. You can bring them to PD to diagnose the problem. Ridwind and probiotic biogaia help ease the colic pain
Hi... you might find this article informative https://sg.theasianparent.com/tips-on-getting-your-baby-to-sleep-longer
Check baby has any colic / gassy / bloated stomach. Bf to sleep? Off the lights in a quiet room.