That's a lot of meditation! I am doing 20 minutes at the moment and I feel similar to you: I still have serious trouble staying focused on anything. Did you keep it up or was there a lasting effect?
I never saw a need to go beyond 30 minutes. In my opinion there is no right way. The breathe is key. Irregular breathing is a problem for many of us if we spend most of our day sitting in front a monitor tightening up.