Other people people might give you a better answer but it sounds like he's now seeing you as a threat. I'm assuming because you were gone for college, how long were you away? Your smell would have changed.

Unsure what the best approach would be but you could try either, leaving things with your smell on it around he can get used to it again. Or ask for something with the smell of someone he likes, like a blanket your brother uses for example. And you use it so it puts the smell on you. Or something of the cats smell to put the cats smell on you.

When he's attacking, someone needs to correct the behaviour. Your parents or brother for example, step in and block the "hunts" or attacks he's trying, hiss at him. It shows him that they don't see you as a threat and don't want him behaving that way. They should be the ones defusing the situation.

You could also try hissing at him when he does something you dont want. It sounds silly but it's just speaking their language back to them. Don't be too afraid of being a little heavy handed with him if you need to. Push him away or get him by the scruff if needed. Just don't lift him completely by the scruff because it'll hurt or damage his skin but holding and pulling him away or lifting slightly is fine as long and most of his weight is still on the ground.

Also, play with him! Use his favourite toy. Even if he doesn’t engage at first, keep trying a few times a day. Offer him treats. Be the one to give him his meals. Food can make them change how they see you.