This AG pool may cause a divorce!

Going on year 2 with this 26' x52" round above ground pool. Last year I upgraded to a 2890 sand pump filter. The pool gets so dirty all the time and chemicals are crazy expensive. I have stumbled onto the bbb method and am so excited to get started. Pool is filling now. What would you recommend to do first? Please attach any get started links to simplify this process. Any help is appreciated and consider yourself a marriage counselor if this pool gets clear and swim ready. (Just kidding). Did I mention I did not put a cover on last year???