I can second the Simi Yellin idea!! My 8 year old was the same way when he was younger, and I must say he’s my easiest kid now – always helpful, cleans up after himself, etc. Don’t know how it happened, maybe starting school full-time? It seemed like overnight, but I hope it works for you too hopefully soon.
Don’t underestimate the power of Tefillah! Even while you are cleaning, talk to Hashem – it helps!
Now my 2 year old is following the same path and I pray every day that he find the right things to keep himself busy… Hatzlacha!