As per several suggestions on this thread I picked up and read Mastery. Have to say I see plateaus in a whole new light, as a good, if frustrating place to be. Plateau is where the real learning is actually taking place he tells us.
To the OP... I counted back and yeah at about 7 months I was in the same fix.It lasted a good while. Pretty much from right after my first test in October until about mid January I think. I'll be testing again next month. It will be interesting to see if I bottom out again like that. As everyone else said just keep going, eventually it ends.