If your frog hasn’t eaten in that long and your not sure about the age you should really bring him to the vet, if he has an internal bacteria infection cranking up the heat will not cure it he will need medication. And you shouldn’t put his heat over 85f for to long of a period of time because if he doesn’t go to his dish or burrow he could dehydrate. Even big time breeders suggest to not keep your frog over 85f, this is usually the max temp for these guys. Another possible problem is he may have contracted a parasite from a bad feeder because this another big reason frogs will stop eating. I really think it’s something inside because from the picture of your frog he doesn’t really look like anything’s wrong, without being a professional sometimes it’s really hard to diagnose a frog over the internet. I don’t know what else to suggest because again he doesn’t look sick from the photo, I wish you the best of the luck and hope he turns around and starts eating for you.