Baby doesn't burp after breastfeeding.

My baby is 1month 18days old.he has become very fussy and he likes to sleep in lap or shoulder specially after evening..most of the time, he stretches his body,grunts and passes gas.when I try to burp him, most of the time he doesn't burp.I have good milk flow,when I pump,it fills 2oz in around 10minutes. but my son doesn't suck much,he feeds maximum 5minutes ,then he pees,poops and sleeps in my lap and doesn't burp.after 5minutes again he cries,again sucks for 2 to 3minutes. he doesn't have sound sleep because of gas problem.colicaids,hing paste,tummy time,cycling..I have tried all,doesn't work.though his weight gain is good and passes urine more than 10 times.dr.said not to overfeed him but whenever he lays in my lap,he automatically turns to my breasts and everyone says his feeding is not enough .but I noticed he sucks even my mom's breast for longer though there's no milk.is it normal?he doesn't have any other activity.only grunting and stretching even in sleep.how can I help him?