I agree with the others. Something is up. Go get it checked out and trust me I know all about Stomach Problems! I've had them off and on since I was 16 yrs old! (31 now soon to be 32 in two weeks) When I was a teenager I was the same way, I couldn't eat, it just made me feel bad. Time went on and I finally got over it (we all figured out it was stress at the time) but later on I had more problems and they checked out my stomach and I had 7 ulcers.
Now I have Acid Reflux and am on medication for it as well as I have to watch what I eat. Not saying anything of this to scare you, but you should get it checked out. Also when you skip meals you lower your metabolism as well as your blood sugars. (I had that problem too in HS, my bs crashing from lack of eating)
Try eating small more frequent meals and go see your dr. Could be nothing, but better to be safe than sorry.