I certainly agree with Jon, TrueBlue, qc111, and Cam. With the addition of more chain, what you already have is more than enough.
I have a 27,500lb sloop. The 45lb
CQR has been my primary
anchor for the past 18 years of sailing from Maine to Grenada (except for the Chesapeake Bay area where I prefer
Danforths and Fortresses). It has held through every kind of weather, including a very nasty 50-55kt night anchored in the lee of Saba in the Caribbean.
The
CQR has been the standard
anchor of long-distance cruising boats for many, many years. Used intelligently, it will do what you ask of it. It is good in most bottoms EXCEPT soft mud and silt where it has very little holding power. But in thick mud, sand, coral, clay, rock, and many grassy bottoms it does just fine.
As others have said, the important thing is technique. Drop your anchor slowly while stopped or moving back slowly, pay out plenty of chain, take a slight strain on the
rode until you feel it grab, pay out more chain/rope, take an increasing strain, then let it sit for awhile before taking a real strain on it. Don't try to set it initially with a strong pull using your engine. Be a bit patient. It will grab and it will hold.
Bill