So here's the thing; you've done the same thing many many times in a row and it's not working. One possible solution is to try to throw more food at it, but do you imagine that THIS is the one thing that's keeping you from getting bigger and stronger?
I would find it far more reasonable to believe that it is the TRAINING that is failing rather than simply the diet. It was working, now it's not. You dropped the weight down, did the exact same thing you did before, stalled out, did that again, and stalled out. You've found the limitation of the programming, so it's time to use something different with different limitations.
Something with a variety of rep ranges, assistance work, a logical and sustainable progression method, etc etc. 5/3/1, Westside Barbell for Skinny Bastards, the Cube Method, the Juggernaut Method, etc. All great programs based around logical principles and developed by successful athletes/coaches with verifiable track records.