Sleep?

My almost 6 week old is still eating every two hours (breast milk from a bottle). He will go 3 hours sometimes and every once in a great while 4 hours. He eats 3.5-4 ounces each time but if I try to increase he spits it all up (in hopes that the extra amount will let him sleep longer-no luck) Is anyone else's baby still doing the same? Is there anything I can do to get him to go longer stretches? I'm dying over here. So tired.