What is going on with my stomach???!

What is going on with my stomach???

Ok, I was a good eater, if not a slight overeater. But ever since I started working again, food is just not interesting to me anymore. I was eating the equivalent of one good meal a day with a couple small snacks, and now I can only eat a little bit once every 3-4 hours or more. If I eat more than that, even just by a little bit, I feel so sick! Since the middle of May, I've lost 18 pounds, and while I'm not complaining about the weight loss itself, I'm afraid of losing anything above and beyond 5 pounds more.
I don't know if something is wrong with my stomach or hormones, but I'm freaked out by this. I appreciate any advice that is given, but if anyone has a real medical explanation because they're in the medical field, that would be just super!
***A couple little side notes: I've been a Type 1 diabetic for 20 years and my blood sugars are under control and I do walk 4 miles a day total commuting to and from work. I highly doubt this is a metabolism thing though. PLEASE HELP!!!!

I once had type ll diabetes which is completely gone now. I, like yourself dont feel hunger that much and subsequently I eat a lot less than I did before and I was a habitual over eater. I have lost almost 100lbs in the past 3 years without trying which is a good thing as I was very obese. My doctor told me that people that overeat have emotional issues(its not what you are eating but what is eating you) and once those issues are resolved many people get this way. Unfortunately, now, I have the same dilema that you do and I do not need to lose anymore weight. So I purposely will eat something that is very high in calories about 2 to 3 times a week in order to maintain my weight.