4 months and sick

Baby is 4 months old today and has caught a cold in the last week. He has been doing fine up until today where he barely wants to nurse. I latch him and he’ll suck for maybe 30 seconds to a minute then he’s pulling off or squirming until I take him off. I can relatch him and he’ll suck again but then pulls off again. What can I do to get him to eat? I don’t want my supply to hurt because he’s not eating but I also don’t pump because I don’t respond to a pump.