My 2 year old is jeckle and Hyde!

[gem31566]

My two year old is so sweet, caring, chatty, helpful and then all of a sudden he turns into an angry beast and he's hitting, throwing things, screaming, crying, shouting! I try to calm him down by cuddling him, reassuring him, putting him in a quiet space to try and calm down and he understands what he is doing is wrong but he just seems to not be able to snap out of this rage!
I have boundaries for him and if he misbehaves he goes on the time out step, treats taken away, no tv time, I've tried good choices chart and stickers, treat box, praise when he's made a good choice but then he gets angry and destroys his good choice chart!

Anyone got any advice on what else I can try please????