Help please! Any one know how to get your baby to stop throwing up? Ive already taken him to the…

Help please! Any one know how to get your baby to stop throwing up? Ive already taken him to the doctor and hes not lactose intolerant. Ive tried interrupting his feedings a few times to burp him like his doctor suggested but ive seen no improvement yet and its been a week. Hes one month old and hes breastfed. His pediatrician doesnt want to put him on any meds since hes only 5 and a half pounds and since hes still gaining weight and having regular diapers. But he throws up after nearly every feeding and im changing his clothes so often that he goes through about 6 onesies a day. I feels so bad for my little guy too, he gets so fussy after he spits up and i know its horrible when it occasionally comes out of his nose. Any suggestions for what i can do to help him not throw up would be great! Thanks!