I am so sorry to read of your loss You really should not feel it was your fault but I know from experience how difficult it is not to feel there must have been something we could have done but sometimes there really is nothing we can do to change the sad outcome. Last year I took charge of 10 very healthy looking Baby Grey tree frogs. We even went and traveled halfway across the country in the most awful rainstorm to get them. At first for about a week all was well then they started one after another to collapse and die. They went from looking healthy and feeding normally to being dead a couple of hrs later. Obviously I consulted a vet and she is good as she specialised in frogs so she did what she could but we could not get the lab results back quick enough and as we lost the last ones we found out it was a little known parasite which destroyed the lining to the frogs gut, there was little which could have been done just as I was assured it was nothing I had done the frogs would have arrived with it. It s still all very sad but I am sure you also did all you could. I hope the other one is still doing well. Thinking of you Jay