Hi Carole! Although it's nice you are helping a friend with a sick frog, you are taking a risk by bringing it into your reptile room. Under no circumstances should you share anything with your animals and make sure hands are well washed before and after handling frog and it's enclosure.
There are too many guesses in your post to narrow down possible causes but will try. Well water is good if you have a current analysis that includes heavy metals which could cause TOS. Without that; need to treat with Seachem Prime or similar. If frog crickets were not gut loaded and neither were supplements used; have more possibilities to include malnourishment and or MBD.
Frog should go to a vet; barring that, then a hospital tank set-up is needed. Would give it a bath in 10% Pedyalite with 90% 80F distilled water for 20 minutes. Following that, offer gut loaded crickets dusted in Fluker's Repta Boost powder. If frog eats; then it's on the way to recovery. If it doesn't; then try again the next day. Please post a pic of frog to see how it looks; if too skinny and weak might need to force feed Repta Boost according to instructions. If you get a fecal sample would be great to have it analyzed and see if there are any pathogens in the frog. Good luck

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