He is 4.5yr old.
Since July 2017 (when his sister started crawling) he has become obsessed with her and obsessed with being horrible to her.
I am crying as I write this so please be kind.
- he will put toys in front of her, wait until she goes to get it then snatch it away
- shut her hand in doors
- make her spit on stuff
- 5 toys that he got for Christmas he has broken (his reason, he wanted to)
And now his new thing he is hellbent on waking her up, at 4am this morning he picked up two toys clashed them together and said her name multiple times, then she woke up crying. When I went through to his room, he dived back into bed pretending to be asleep.
I have a 7 month old now too and the behaviour is transferring onto her. (He will throw toys at her in her high chair) or he will bang toys off the floor to get her to look at him. If she does happen to look he will run away. And the other day he has started to pick the wall off

I am exhausted, I feel like I'm doing something wrong as nobody in the history of the world seems to experience this. I don't think we are all ever in the same room for too long as I cannot cope. I don't know what to do anymore. Does anybody have any advice?