HELP! very jealous 2 year old

It can be hard for a child who had you for himself for 2 years to adjust to the added kids because now he has to share you and typically toddlers don't like to share. I know it might be difficult to achieve, but you do need to spend alone time with him and each of the kids. It doesn't need to be hours, but some timedoes need to be made for each. This will help because he needs to feel he isn't being replaced or pushed out. He is old enough for a chart with stickers that shows consequences and rewards. He needs to have severe consequences for this behavior every time it happens and the child that is the brunt of the action needs a big reward where 3 yr old can see it. So if he throws a toy, the toy goes away to TO, he is in TO and the hit child gets ice cream. The stickers chart can help because you can do a daily rewardfor his good behavior. Don't forget to praise him for any good behavior he does either. Sometimes we forget adn just scold for bad behavior, but rewarding good behavior has a greater effect toward changing their actions than anything else. My time out is severe. You must remain in the spot for the time, you can not whine cry or otherwise talk while in there either. Every time you get out or cry, the time starts over and while you're in there not following the rules, the other kids often get to do something really fun.