You are correct, the only way for you to have hope is to pray that the increase in the price of bitcoin outpaces the pace at which the difficulty mining rises. The one good factor is that the electricity rate is set, so this becomes less of a factor over time as the price of bitcoin rises. I really like the way you break it down mathematically and graphically. You think like me. Following.
RE: True lifespan of Genesis-Mining Open-Ended Bitcoin Mining contract