Hi mummy,
I did the same by throwing away the watery part when I pump out to let my lo consumed the hindmilk. But it was't helping much though because the he vommitted out too.
Try burp him halfway then continue feed again. If after burp, put him upright or prop up for awhile before letting him lie down.
I can only say it will get better as they grow older. Hang on there mummy.
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