No longer sharing

Pa

As soon as baby came into the picture (Feb 28) my June baby is suddenly not sharing, hitting, and throwing tantrums when playing with others. He’s also beginning to spit on us and hit us when he’s angry. Does anyone know what we can do or how we can help him through this? We keep him involved with everything, we give him one-on-one time, when one of us attending the baby the other is attending him, our families are both treating him exactly the same as before, but somehow the transition is still very tough for him. He is extremely sweet with the baby and doesn’t show any jealousy or anger towards her at all. He willingly helps out, he takes care of her so much, but he’s becoming a very difficult kid when he used to be such a sweet and easy kid 😭😭😭