You left a live mouse in this cage for several hours unattended??? First, that was a mistake right there. Not sure bout the bloating, but it could have been an infection caused by a possiable bite from the mouse or several.
Now, lets think a little bout water heat. What do you do on your stove when you try to cook noodles? You boil the water by increasing temps to cook the noodles. You basically in most cases created that senario. Placing a bowl with water on top of a heat pad for however long you left the snake subjected to prolly overpowering temps in the bowl without little exscape. Basically, without relizing it, there is a very good possiability you cooked your snake alive.
In the future, for senerio purposes, if for exp the snake did actually get bitten and there was a scar or something more critical bring the animal to a qualified vet if your unsure or little doubt what to do. Why waste your time if your not certain when someone with hopefully a degree in herpotology and degrees in animal and medicine care might have helped. In the future, again for senerio purposes, clense the wound with an anticeptic. I've used neosporin and a cutip with rubbing alochol and lightly dab the infected wound, with rescues I've taken in or bein involved with injured animals.
For the record, going off feed for 2 months is nothing and is to be expected from Sept-Dec. If your snake had decent wieght in grams, prefably 1500 and wasn't losing sugnificant wieght measuring with a gram scale, you might have basically got worried about nothing and cause more problems for yourself and the snake. I suggest to going back to basics and start reading on basic husbantry of ball pythons and expanding your knowlege with all species. If you would have done the research beforehand, you would have known, leaving live pre unattended is a stupid risk to take for any keeper with any species of reptiles.
Appogize for coming out bein harsh, but if it were me, I rather have someone give it to me streight then trying to sugarcoat things.
Feel free to email me with any questions.