Sibling rivalry i really need some help and advice?

it looks like your eldest is just jealous of this new baby taking up your time and attention. you have to sit him down and talk to him, explain to him that his little brother needs to have some toys too, and perhaps tell him that if he doesn't share his toys, no one can have them? but violence should never be accepted, so be firm with him when he hits out at your youngest. i know you've said you try to spend time with them separately but maybe you just need to balance it out more. this is definitely just a phase your eldest is going through, but it's difficult when a child who is normally very well behaved starts acting up. just try to be a little stricter with him and he'll soon get the message.