I breast feed my baby

Is every 2 hours during the day and then every 3.5 hours at night enough? I physically cannot do more. Pediatrician said he lost too much weight after birth. I go back in a few days to recheck and I have been trying every 2 hours but at night I can’t. I have started pumping since then and having my husband help when I really need sleep, but he works early in the morning and long hours outside, I don’t want to make him get up more than he already does.