I have had a pacman frog for about 3 to for months now and its been getting cold nowadays. the only heating the frog has is a lamp that is on 12 hours a day. Sometimes the temperature drops to 60 degrees f and 55. Im planning on going to petco where they sale heating mats and stuff like that, but what else would i need to regulate the frogs temperature and make it act normal again? lately it hasnt been eating much and i assume its from the worms i fed it a while back, they were superworms and its about 4 inches long, and albino.
Heres what i plan on buying it

Zoo Med Repti-Therm UTH Under Tank Heaters at PETCO

Also
I have a heating rock from my past lizards that i gave away and im wondering if i can use it for the frog aswell