6 weeks 4 days old baby. 3-4 ltrs daily)

My baby is 6 weeks 4 days old. Completely on breast milk. Weight 4.2kgs . Recently he started having issue while passing gas and stool and puts a lot of pressure, sometimes even when breast feeding .. sometimes cried too. For gas issue we put hing around his navel since colic aid didn't help much. Recently he has started putting a lot pressure while passing stool( he pass stool once or twice a day). Last night while sleeping he started putting pressure again and making sounds (stiffed his hands downwards completely) so I helped him by cycling his legs and folding legs upwards and he passed stooled but after sometime again he started making same sounds and putting pressure while breast feeding(btw he feeds in every 2 -3 hrs ) . Need help as I have heard that breast milk is easier to digest. People near me suggested to drink more water so that baby can pass stool easily(I drink 3-4 ltrs daily)