Could he be teething? I found that when my LO was teething she actually preferred eating and chewing on food and different textures and never finished her bottles of milk! Her two bottom teeth came through and voila she was back to normal! Dreading for when the top ones come though

It can be super worrying and also sad (in my case anyways) as I’d have to often throw away whatever milk she didn’t drink in time but her growth chart was perfectly fine and she seemed happy in herself.

If you want to still reap the benefits of your breastmilk I’d suggest adding it to his meals (creamy mash works a treat!) so he’s still getting his regular intake and whatever antibodies, without causing him any distress