Hi Jack
Sorry to hear about your loss of anchor, I think we have all been there.
For the future, I have found that if you can not lift the anchor by the alderney buoy, let out some more warp, (rope), if the line is too short it can not lift and pick of the anchor correctly.
It has worked for me on a number of times.
Check out ebay for a cheap replacement.
Regards
Coddy