I'd appreciate some information about it and if I can get my quarry back without mining frantically for half an hour.
I'd say you used landmarks to define your quarry, and put the quarry inside the area to be mined. The little yellow/black box in your photo is clearing the area for the quarry frame. It destroys blocks in the area, and if you placed the quarry inside the landmarked area, it almost certainly destroyed your quarry for you.
That being the case you'll have to create a new quarry. Let the quarry use the default area this time, rather than using landmarks. The quarry will show you a preview of the volume it will clear before mining proceeds using a yellow/black line. Make sure nothing is within this volume before you connect the power.