I'm lucky enough to maintain my weight despite eating McDonald's 3-5 times a week (Lunch time at work since I've only got 15 minutes) on top of drinking a lot of soda.
My advice would be eat healthier, but don't cut out the things you like. You should just simply limit yourself gradually. A diet shouldn't be miserable.
I get a similar weight gain effect from my ADHD meds and birth control. When my ADHD meds are working during the day, I don't get hungry at all and can even forget about lunch because my metobolism falls off a cliff into a crater. Then my meds run their course, my metabolism scales the cliff face, drags itself out of the crater, and I'm eating more calories at 11PM than I ate throughout the day. Through this entire cycle of metabolism up and downs, my BC is constantly making it easier for my body to turn unused calories into fat for some reason I can't explain. It's all a bit confusing and one more meal can add 3 pounds out of nowhere that are nearly impossible to lose.
Therefore, I had to figure how to eat in a way that my body will use the food properly. If I eat useful calories throughout the day, I can eat most of my useless calories at night because my metabolism is more active when my meds are inactive. That means I eat most of my fruits, veggitables, whole multigrains, and other heathy stuff during the day, and I can treat myself to pizza and ice cream at night as long as I keep the treats in moderation. As long as I don't give my body more calories than it can process at the time of day I'm eating, I don't have a ton of unused calories turned into fat before my metabolism drags itself out of the crater. I have the normal amount of calories turned into a heathy amount of fat.
In other words, the same way Pataflafla can get away with McDonald's 3-5 times a week and tons of soda around lunch time, I can get away with eating 2 slices of pizza and a small cup of ice cream in the late evening 1-2 times a week. It's just the way our bodies work. Once you find out how your body works, the weight should decrease and then stabilize. I would love to be the 130 pounds I was in high school, but I'm happy with being 140-145 pounds now that I'm 27 and physically healthy.
I don't know Tabby's body better than Tabby, but I would guess 40 of the 60 pounds gained could be lost not by diet but by changing eating times, how much is eaten at which times, and what is eaten more often and less often. Even the Cheesy bread bits can stay on the menu, but you may be eating the wrong amount at the wrong time of day too often.