Hello,
Hang in there---this takes time.

See how things go-- if he begins to look lethargic and does not eat at all; you will; need to be prepared to do a fecal.
So if you see a poop be ready to get it to a herp vet. I may be his only poop for a while.

In the above post - the vet will give you directions for this - It can be mailed.
Or, make some call to locals vet and find one that is willing to do the fecal test w/out actually seeing the frog.

Wrap three sides of the tank with a dark towel- it will help him feel more secure.
Keep the the enclosure in a warm and quiet area -away from the window.
Handle him only if necessary. Be sure the feeders are not too big.
Give him a day or two; hopefully he will come around. Count the crickets you put in.

He will likely need to be in a separate enclosure for quite some time.
I believe you should convert a 10 gallon - so he has more space. ( Screen lid covered most of the way with plexi or glass rom an old picture frame.)

There is a photo of a 10 gallon quarantine tank in the link - in the previous post.

You could wet the paper towel with the 10:1 ( water: pedi) solution for him to sit on for a while.

Please keep us posted