Don't worry. It is quite common behavior but u need to figure out what is the cause behind it. I listed a few possibilities:
1) milk strike - baby refuses to drink, drinks little, can be calm - some parents resort to force feeding which is a long and tiring process or just smaller quantities at higher frequencies
2) teething - since ur baby is putting hands into mouth - this could be a longer phase - give cool tethers and can also put teething gel on the gums to numb the gums especially before feed - can buy any brand over the counter
3) teat issue - the teat is too slow for baby - consider changing the teat and see if baby will drink more - they may just suddenly want a bigger teat and feel angry abt the milk not coming fast enough
4) a combination of the above
5) check and see if baby have ulcers in the mouth (lips/throat)
Hopefully u can solve the mystery soon :) if purely milk strike - then just have to wait it out
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Mum of 2 michelin baby haha