Sherry, what is under the paneling. It has been typical lately to put up thin paneling and that needs drywall to support it. Unless you are sure that you have panels that are a half inch thick, you can be pretty sure that there is something stronger under there. Even then, there will be a chance that the old drywall is still there.
"Patching" the grooves is a mess and the probability of future problems is strong. It will be better to remove the paneling and repair or replace the drywall that is there.