I had the same issue. The county won't make a change to your evaluation without an appraisal from a professional, objective source. Contact some appraisal companies for the best price then take your appraisal and ask the county to reduce the valuation of your property accordingly. Just hope the independent appraisal is less than the county's!
I am a realtor with Re/Max and live in Huber. e-mail me and I will get your information and do a comparable search on the Multiple listing service of homes sold. This would tell you if homes like yours are selling above or below what yours is tax appraised for. My e-mail is <email@example.com> I look forward to hearing from you