Ouch, this brings back painful memories, I started mining at the start of 2017 but didn't have confidence that eth would last long term so I was selling my mined eth every month. I remember how each gtx1060 mined close to 7 eth over the whole year back then.
I learned my lesson after that. I always save 50% of my mined coins and mine a variety of coins now. My hope is to mine at low diff for a year or two before the next bull market.