Yes, players do check their rankings mostly every week for several reasons. They need to know their exact ranking for tournament entry and for seeding purposes. Obviously, players need to have this information on hand. I think every player has a good memory of when they have points to defend from the previous year. I try to spend more time preparing to play well rather than worrying about the points to defend.
Most players select their tournaments based on their current rankings.
I try to mix some larger WTA events with some Tier III and Tier IV events to have a variety of play. When there are two tournaments, I usually select the one with my favorite surface or one that I have played in the past and have liked. The only corrective action I've tried is to take the pace off, but that makes my strokes tentative, and my opponents jump all over me. Since you are having trouble finding rhythm, maybe I can suggest a few things to help. Pretend that you are 10 years old again and need to check your swing, balance, etc.