Hi My Little One Is 4weeks And For The Past

Hi my little one is 4weeks and for the past week he hasn't been sleeping much. He has a very disturbed sleeping (he moves around cries and makes sounds and falls back to sleep very often) and wakes up crying every 1.5- 2 hrs. I am giving him more formula feed, each feed is upto 3.0 ounces and at times he has only 2.5 ounces. He is up most of the night. Plz help