My fired bellied toad is bloated

[Classpi]

1. The tank is 4.2 in height, 11.6 inches x 11.8 inches width. Here's the tank Amazon.com: Lee's Fire Belly Landing, Round w/Lid, Handle, Tray, Plant: Pet Supplies The wat

2. Only one frog. No fish.

3. Water source is from the sink. I use Top Fish water conditionor

4. Water temperature is room temp, no heating

5. N/A

6. No filter system. The aquarium itself has little holes at the bottom where debris will flow out when the cage is picked up

7. Pebbles and a landing in the middle.

8. One artificial plant, and a rock hide-out.

9. Live crickets. Once a day. (Since he doesn't more than one a day)

10. Nope.

11. No lighting.

12. A day ago (believed)

13. No. But i have been finding this clear mucus with little black dots in it.

14. In the second picture you can see the mucus on the landing

15. I don't know. He was a light green when we got him 2 years age. Now's he a dark green but i believe that is because we gave him mealworms last time. We don't give him those anymore

16. For about 2 years or so.

17. Captive bred

18. No.

19. No.

20. High.

21. I clean the tank almost every week

I'm probably don't have the right stuff to take care of him, don't I.
I've been thinking of getting a new, bigger cage for a while. But because of the way he's been acting, I'm thinking twice about it.
Should i get a new tank and maybe a heat light?

Now he is "coughing"