The theory behind forming a Limited Liability Company IS to limit personal liability to the assets ofthe LLC.  They are a hybrid of partnership and corporations law, allowing more flexibility than corporations do but with more protection than partnerships.  A person in the LLC is called a "member" and generally speaking members can not be found personally liable for corporate debts.  Here the "DBA" may be the issue and local case law may need to be reviewed to see if adding this in some way exposed you personally or rather allows a plaintiff "pierce the corporate veil" of sorts to go against you personally.  You should speak with a corporate attorney in your area.  Good luck.