help is this just a growth spurt?

Hi my baby is nearly 7 weeks.. last week he was admitted to hospital he had a virus on his brain couldn't breath so was on icu for 3 days after that he bounced back was chugging his milk another 2 days observing him they let us come home on Monday.. since then he's slept less and and is constantly routing for his bottle.. he's still drinking plenty I've no worries he's not drinking enough but he's very fussy before the hospital he would have between 2-4 oz  every 4 hours now it's like he's just bitting and bobbing (still having usual amount) just in bits and bobs before the hospital he was the most content baby ever only time he cried was getting out the bath now he's constantly crying every time I put him down.. he's still very aware and has much longer awake periods so I'm not worried about him being unwell.. he falls asleep for 10 mins realises he's been put down then cries for his bottle then when I put it in his mouth he throws his head round like Hes Never been fed then just messes with it we've barely slept in 4 days I'm really hoping there's a light at the end of this really long tunnel anyone else been through this?