Fire rated drywall for room next to garage?
The fire protection is for fire traveling from the garage to the living spaces, not vise versa.
The garage is to be separated from a living space with 1/2” gypsum board installed on the garage side and with a 1 3/8” min. solid core door. (See ICC R309.2)
In addition, if a living space is above a garage, then it needs to be separated with 5/8” Type X gypsum board AND no sleeping room can open directly into a garage.
Your existing wood paneling on the living side is acceptable, as is.