Hello welcome
The substrate is unsuitable. Horsfields love to burow. Plain ordinary topsoilk is all he needs.
Your temperature is too high. 20 cool end & 30/32 warm end is fine. How big is the viv? It needs to be long enough to provide a temperature gradient (so lamp at one end) A table would be even better as less humidity
They won't eat if they can't see the food. I would up his baths to daily for the time being & persevere with the eye drops, which you may need to gently rub in to manipulate past the eyelids.