They are okay and the message is the same, maybe except for the last one. "You're responsible for why I'm like this." = This still means 'you' are the reason 'I'm' like this. But by saying 'you're responsible,' it sounds like putting the blame on whoever 'you' is. They can either be good or bad depending on the situation and delivery of the message. Yes, even the last one can be good. For example, You make me a better person. I now wake up early. I eat healthy. I even exercise. Because of you. You're responsible for why I'm like this. << If you say this with humor, it sounds good. * I suppose I should also add it also depends on your relationship. If you're really not that close, this is just creepy. So, context and delivery.

* It's you why I'm the way I am. => It is because of you that I am the way I am / You are the reason (that) I am the say I am. * It's you why I'm like this. => It is because of you / You are the reason that I am like this. * It's because of you why I'm like this. (why => that) * I'm like this because of you. Good. * You're responsible for why I'm like this. (Ok, but I would prefer: You're responsible for the way I am.)