Hi there, I'm Dr. Sara. I'm a licensed veterinarian who works exclusively with cats and dogs. I'm really sorry to hear that your guy has had so many troubles in his life. I'll do my best to help, but I'm afraid that I'm probably not going to have the key to everything, especially without being able to see him in person and review all of his records.
You said, "... By the time they thought they knew what it was and how to possibly fix it, I was past broke and they wanted me to spend a least another grand." - what was it that they thought was wrong and what did they want to do to fix it?
Did your vet see and appreciate this odd swelling that you are seeing? Any firm swelling like that merits more investigation with X-rays, an ultrasound, or possibly even an exploratory surgery to see exactly what's going on in there and get biopsies. I have seen cats with megacolon (severe constipation) develop abdominal distention in specific areas, but they always are having a difficult time defecating and are having very firm dry stools, which it doesn't sound like you're seeing. The eating of litter does concern me a little as well, in that it could indicate that he's not digesting his food properly. Odd gas distentions can happen with dietary intolerances (like lactose intolerance in people - they can get very gassy and uncomfortable) or inflammatory bowel disease. Special diets like prescription hypoallergenic diets or easily digestible prescription diets can alleviate a lot of GI troubles in cats. If we know the issue, we can suggest an appropriate diet.
Ear infections can be a random "fluke" thing - so I wouldn't be too worried if he had developed one - as long as it responded well to medications and he's over it. If they get recurrent ear infections, that's when I get concerned for an underlying problem like a tumor in the ear canal or a benign polyp. A mass of any sort in the ear canal causes repeated ear infections. However, if it resolved like you said, then it's likely nothing to get overly concerned about as long as it doesn't recur. I would definitely like to know, though, what diagnosis your vet came up with and what they wanted to do to fix it.