I have the same problem that you are dealing with. Mine is now completely blind. My daughter gives him a shower everyday so he drinks and feed him by hand in the shower also that's the only way he'll eat. She has kept him alive for over a year now and he seems very happy when he hears her voice...
I just use organic vegetable from like a Whole Foods. And then I get that Cricket crack stuff. From time to time I don't know how serious other people do it. But when I get my order crickets I always make sure they're eating for over a week before I feed to mine. Sometimes you just don't know...