It doesn't appear that the lug bolts are rounded or significantly damaged, which is good. Apparently and logically the bolts are made from stronger material than the tool. These appear to be standard hex/Allen bolts so finding a replacement tool should not be too difficult once you determine the hex size for both the lugs and the lug wrench with your vehicle. If these are factory provided lug bolts, then the search should be even simpler. If these are aftermarket lugs you may start with a tire shop that sells aftermarket wheels and lugs.
-Rod