My cat has suddenly become very aggressive towards me and my family

Hello, my male neutered cat Toulouse, has suddenly become very aggressive towards me and my family, he is about a year and 4 months old, he used to love being brushed now he bites, scratches and leaps on me. He doesn´t pur anymore and runs away when we try to cuddle him. He also randomly attacks our legs and scratches sometimes till bleeding point.
I am going to go to the vet to check if he´s maybe ill.
But does anyone know if this is normal for a car his age? Is it some sort of phase?
Thanks for all the help :)

Sophie