Help!!

I’m actually going insane! My 7mo LO cries every night when he gets put in his cot and needs to be held for literal hours before being put down, every time we try put him down he cries, it’s literally 4:20 am he’s been asleep since 3:40 and will not let me put him down and every night I have to hold him till around 5/6am till he’ll go down I’m actually starting to lose my mind! He was never like this before he’d be up have milk go straight back into the bed like I cannot carry on staying up for hours holding him I’m so freaking tired I don’t want to wake my husband cos he has to work so I can’t keep putting baby down and picking him up because he just keeps crying and waking my husband like I actually cannot do this anymore I am at my wits end!! Also please please do not suggest bedsharing that is an absolute no no for me