4.5 week old falling asleep bf

lvasilen

My son used to fall asleep at the end of his feedings, usually 30 mins. The last 2-3 days he falls asleep every 5 mins or less. I talk to him, sing, massage, do,  skin to skin, burp him, switch sides, play music, read, nothing is working. I don't think he is eating more efficiently as when he does wake up 10 mins-1 hr he wants to eat again. 

He had a 3 week growth spurt, not sure if he is going through another? I feed on demand but this seems a bit crazy for long term. Thanks!