I’m gettting my cat neutered within the next few weeks, he’s 9 months old

He’s been having some issues with agression: swatting, scratching guests, biting, pouncing. Last night he sunk his extremely sharp teeth into my hand DEEP and drew blood. This isn’t the first time.

I’ve been around him since he was born and I’ve had him since in he was old enough to be away from his mother so he’s never been homeless or subjected to any trauma. The only explanation I can think of for his aggression is that he’s not fixed

If your cat was aggressive and you got him fixed could you tell me how long it took to for you to see improvement in his behavior

Also, how long is the healing process and is there anything I can do to make him more comfortable? Does he have to wear the cone?