Fix what you can
Some parents find it helpful to make a list.
Checking for specifics night or day reguardless of your level of fatigue.1. Basic needs: hungry, laying in pee, poo or spitup 2. Hot with fever
/cold-?Need eval. Or warmer outfit. A lot of fussy babies are simply overly tired & the best you can do is create a good sleeping environment& help them settle. If all fails schedule a visit with you pediatrician.