My baby was like that during first two weeks or so, but now is much better, and only eats for 9-10 min on each side. I read some articles afterward, and found out that there could be several causes: Baby has jaundice, epidural was used during labour, or induced labour.
Jaundice will make baby feel really sleepy and so they will sleep during feeds, but sleeping during feeding will make them eat less and the jaundice will get worse, and it becomes a cycle.
Epidural will enter baby's body but baby's liver is not mature enough to process it, so it will cause larger effect on baby than mother. Baby will not be able to suck that well while feeding.
Medical substances used to induce labour could affect the milk production of the mother.
My baby had taken supplemental formula for 3 days, and once he's less dehydrated, he's back to good feeding again.