So I bought my Whites tree frog from a PetCo nearby and he was just a teeny thing. He ate and grew normally for several months ( I got him in June)... Starting in late December I noticed that he no longer would sit at the top of his favorite leaf and didn't move much at all. This progressed over the next few months and he started to move less and less... He stopped eating about 2 months ago and has had one cricket in those months... He has gotten extremely thin and cannot move himself around, whenever he tries.... he ends up flipping over on his back and trying to get himself back up... He has not pooped in forever and we have to put him in his waterbowl and take him out....
So I called someone who knows about frogs, and it turns out that we weren't giving him enough Calcium and that it messed up his growth... I have been trying to feed him calcium laced crickets, but he wont eat, even when I hold it in front of him.. I have put him in a calcium bath, but that just caused his skin to grow moldy spots.... He is slowly starving and I can see him struggle to even move and it just breaks my heart... And I know that it is completely my fault because I didn't feed him properly...
What I want to know is if I should put him down humanely (I've read a few methods online--- mostly alcohol solutions) or if I should keep trying and just let him starve?

Other info:
Temperature -- 75 degrees to 80 degrees
Water----- de-chlorinated and changed regularly
Humidity---- about 80 percent
Substrate---- Coconut fiber
Food---- Gut loaded crickets (now laced with calcium)
He has a day and night heating lamp
I feel just horrible and I wish I could have caught this sooner before it was too late... my poor baby