Well, Loki, maybe it means you're getting better! If you have been ill and unable to eat for a few years, it might be hard for you to adjust to actually being able to eat again. And now, having a colostomy, it might be awhile until your bowels adjust, so you could well be paying close attention to your diet for a few years.
I agree with MMSH that protein is something you should try to incorporate into every meal, as it will keep the hunger pangs at bay. Protein doesn't always have to be meat; legumes like lentils and chick peas are a good source of protein too. So is peanut butter. You will need some good fats as well, in small amounts (olive oil, avocados, nuts). Generally, the simple carbohydrates that don't give us much nutritional value (refined sugar and flour) don't do much for our hunger either. Best to keep those to a minimum. Complex carbohydrates, like whole grains, take longer to digest, so they keep you feeling full for longer. I have eaten oatmeal for breakfast most of my life, but I discovered farro, an ancient whole grain, a few years ago, and I find it keeps me full for longer than oatmeal does. So I am still learning too.
Loki, do you have access to a dietician? If you do, it would be worthwhile to spend some time with one. Learning how to eat properly, especially with an ostomy, can be frustrating at times. If you could consult with a professional, even for an hour, it might save you a lot of time and angst.