Happy New Year and sorry to hear.

What year and model do you have? There are several on ebay now but you need to make sure you get the correct one for your model.

Here's a link to a new one from the same vendor I used to replace my driver mirror assembly on my 4.8 (you just need to transfer mirror cover and mirrror to the new assembly.

BMW X5 E53 DRIVER SIDE LEFT HEATED POWER FOLDING MIRROR - eBay (item 370467526858 end time Jan-16-11 08:00:08 PST)