I also commend you on doing as much research as possible before taking on a frog for a pet. Great job:

Welcome to Frog Forum.
Your heat pad is probably fine. Remove the desk lamp it is probably causing unnecessary stress and hurting her eyes. Go out and buy a Fluker's 5.5" Clamp Lamp with dimmer. The dimmer switch will allow you to adjust the heat and light output of the heat bulb. Now the heat bulb MUST be and infrared. No daylight bulbs or basking spotlights of ANY kind. Be sure that the bulb is no higher than 50 watts. 50 watts is also preferable.
When using Saran Wrap only wrap the sides of the lid and leave a gap in the center to place the lamp Cut a hole in the Saran wrap on high ends of the lid so that air can circulate through the top of the lid. . The lamp will raise the ambient air temp which should be as stated by Graham at 80°, but no higher than 85° during the day and 75° to 79° at night. Hover around 78° though. Humidity should be 75% to 80% and substrate moisture must be moist or heavily damp, but not mud.
Try Night Crawlers to see if he will eat those. If you can find Hornworms(Goliath worms) they would also be good to try.