First off nice numbers kid. How long have you been at this "plateau"? I know one of my training pals seems to think hes at a plateau but hes really not he just isnt getting results as fast as he used to and as fast as he likes.
That happens, its easy to see gains when you first start. Lately hes been hindering himself from making more gains because of this. I say this cuz I wouldnt want to see somone else make the same mistake.
You stoped taking whey, is that it? If you've scaled down your routine at all give youself some time to get back into it.