Tiger salamander not eating

[salyluvr]

I have a 4 year old male Tiger that is refusing food.
I have had him for about 2 months or so now.
He's on coco fibre, temps are 60-65 and the humidity is at 70%
He was eating normally up until about week ago now he is refusing crickets, wax worms, nightcrawlers and a pinky.
Daytime he's in his hide or burrowed and early morning he is sometimes on top of his hide or in his water bowl.
I was told that there was an appetite stimulant that I could give him but was hoping for any other helpful advice here.
Thank you all for your time.

 

[John]

I personally don't recommend coconut fibre and I've never kept them on this. Regarding the humidity, it sounds pretty wet - do you have good ventilation for him?

 

[Jennewt]

What kind of lid is on the tank? Has his appearance changed at all? Is his current temperature warmer or colder than it was over the past 2 months? Does he look fat or thin? Was he previously eating pinkies?