Does this apply even if I have an LLC with my name?
TBH this scares me quite a bit since we have all the family’s emails tied to the domain, not only would it be a huge pain to lose it but also a security risk. Weve had the domain for 10yrs or more at this point…
You don't have YOUR_LAST_NAME.com as a website, right?
You probably don't have anything to worry about. Having a domain that does not have a business attached means you're clearly not trying to do business on someone else's name. That takes away at least one of the 9 tests for trademark infringement.