Sleeping cycle and refusing to finish milk

Hello, our baby boy is 7 months old and he doesn't sleep in a long stretch. It could be around 30 to 40 minutes for each cycle. He then wakes up and cries. We either have to hug him going around the house to put him back to sleep or latches on his mum.

Another thing is he recently tends not to drink his milk completely. He drinks like 20 to 30 ml and then refuses to finish his milk and wants to play. Even at night when he is super hungry and sleepy, just latched on his mummy for about 2-3 minutes and then sleeps. And again he gets hungry and he will wake up and the whole story again.

He is teething and he is in teeth pain we all know. But I really appreciate any advice or tips. My wife is tired like all lovely mums and I really want to help as much.

Thank you.