Use a 50 watt bulb. Does your lamp have a dimmer switch?

75 watts is to high. 60 watts is pushing it. Get a UTH and place it on one end of the 10 gallon.

90% humidity is to high for extended periods of time.

Water should be changed no less than every two days except when the frog enters the water then it needs changed immediately or that day.

If the frog is never handled then how do you remove the frog to clean the enclosure?

Do you have your screen top covered with plexiglass, aluminum foil, or Plastic Wrap?

Have you ever offered your frog Earthworms/Night Crawlers?

Is there any discoloration of the skin?

Any changes in activity other than not eating including listlessness, lethargy, runny fecies, excessive shedding, not burrowing, staying burrowed, or flipping over on it's back?