If the %RH in your home is <50%RH, you will freeze at 68^F. Check your %RH and temp to help us comment on your settings. Also what is the supply air temp/%RH? It is possible that the cooling coil is not very cold. Most occpants and equipment mfgs suggest 70^F, 50%RH is a minimum temp.
Looking forward to your post.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"