4 month old as cranky as ever

4 month old is suddenly as cranky as ever for about 10 days now , very busy biting his own hand & fingers all the time , drooling & simply screams as if he is not able to put all his fingers into his mouth , even otherwise simply screams (not sure if there is an issue / he is experimenting his voice) , the minute I take my hand near his mouth tries biting it , drools & tries to bite everything, sleep is reduced , rubs his eyes all the time & it becomes red (bothers me a lot) , wants to be held all the time .

We thought since he drools so much may be it’s time to introduce solids & gave him rice porridge (well mashed & boiled) which he loves but no changes in the crankiness & biting behaviour.

Eats ok no complaints, weight gain normal.

Is it normal at this stage or am I not seeing something ?

What could it be ?