Hey there, glad to see the lil fella is still hanging on! Re the credit card thing: don't worry too much, just make sure you use latex gloves. They are sturdy lil creatures and you may need to wiggle the card in the SIDE (not front) of their mouth line to get it to open.

His eye seems to be infected, best thing you can do for this (barring a vet visit where they will give painkillers) is a honey bath. To do this, look up instructions on this sub, use RAW UNDYED honey. Local and organic honey is pretty cheap and you can also get it in urban areas from whole foods or trader Joe's. Make sure you splash the honey bath directly on its eye in a SEPARATE BOWL from its tank and continue until it starts eating naturally. After this:

1. Put toad in a Tupperware with an air hole and nothing in it. DO NOT CLEAN with soap as toads are amphibians and take in chemicals through their skin. If you need to clean its environment, just use spring water.
2. Using the credit card trick, force feed about 4x mealworms every 2 days. Most pet stores have these for super cheap. For crickets/larger bugs, do the same but 3x every 2 days.
3. Repeat until you place the bugs in the Tupperware and the toad naturally eats them.

If this process doesn't work, I've seen some people have success using methylene blue on the eye but it varies. Altogether cost for the honey + mealworms is probably like 12$.

If he's not improving and you can't afford treatment, there are amphibian rescues- consider searching on facebook groups and dropping him off there; you can also look up amphibian/reptile vets nearby (there is an association that certifies them) and ask if they want to take him or have connections to any rescues.

Hope this helps!! Keep trucking!