Baby isnt sleeping

My 4.5 month old will not sleep more than 1.5-2 hours at night. He does not nap more than 35 minutes throughout the day. Total he probably sleeps 11 hours. He's been doing this for 2 months now. We need sleep! Any advice?

- He has a bedtime routine every night. He does not take a paci and wants to comfort nurse every single time.