I actually think Godaddy is in the right here (and I don't say that very often). You've created a domain related service that could be confused with their trademark. Had you created an auction service that catered to any other niche I think it would have been ok because you were in different service categories. But no. You choice domain names.

Also, Godaddy own gomommy.com since 2002. You registered this name... last month.

To top if off, you're linking to Godaddy auctions with many of your domains. So if I click on many of them I end up on GoDaddy.