Crestie health problems

[Pareeeee]

I'm babysitting my cousin's Crested Gecko, Jack, for a week while her and her family are away on vacation.

His condition has gone downhill since I babysat him last summer.

His toes are swollen and not sticky, he can't climb. It looks like signs of low humidity/bad shed to me, but since I've never had any experience with even one health problem with my Crestie I can't be sure. Also something is wrong with his tail. Please see attached album of photos here: Poor Jack - Imgur

I feel bad since I'm the one that recommended they get her a Crestie. When they first bought him he was healthy, and I gave them all the information they needed to care for a Crestie.

When she gets back I am going to recommend she cover most of the screen top as I believe that is where the humidity is all going. I've covered it with a damp rag for now and misted the daylights out of the enclosure. Got the humidity almost to 80% now, from what I'm guessing was about 30% before. She apparently sprays down his enclosure every night, but I fear the screen top has negated any of the effects.

Yes, he is fed CGD.

What else can I do to help him out?