Hello, I am sorry to hear about Fudge's behavioral changes.
I believe that the best place to start is with an examination and a geriatric blood profile to try and figure out why he is behaving the way he is. If finances are tight many laboratories offer a mini panel that hits the highlights and allows you to see if his organs are functioning normally for a reasonable price. In some dogs as they age their organ systems don't work as well as they once did, and waste products that their organs usually filter out build up in the blood stream and that affects brain function. They may behave much differently because their brain function isn't normal.
And changes in organ function sometimes leads to abnormal cravings as well.
The other possibility given his loss of housebreaking habits and confusion is that he is experiencing senility, not uncommon at his age. These dogs often forget their housebreaking, seem more confused at night when it is dark, cannot seem to remember whether they have eaten or not, sometimes will eat things that they normally would not, and seem to pace, looking for something they cannot find. They may all of the sudden get into the garbage or chew up things when they never displayed these habits before.
The only way to know for sure what is going on is to check his organ function withsome blood tests.
If his organ function is normal there are medications that can help with senility and the associated anxiety, such as Anipryl (L-deprenyl or selegiline). There is also a diet formulated for older dogs high in the particular trace minerals and supplements needed for healthy brain function in older dogs called Hills b/d.
I must warn you that these medications and the b/d diet doesn't work for all dogsand they may not work for long but they may buy him some quality time and helpwith his confusion.
Please let me know if you have any further questions.