I thought the daddy issues were because he never recognized her, although his absence might be a underlying cause but apparently while he's present is a good father, does not excuse him but at least it can be seen that so far he was a positive figure.
I think that he was already past the point of no return before he knew Nagi but for some reason he didn't think that alterantive until Nagi put it in his head, now that he has a taste of what would be like to escape his problems then he wouldn't want to come back.
I would say that he needs...