Diet versus exercise, what contributes more to pure weight loss?

Sometimes I go over, sometimes I don't even get past 1000 calories because I feel sick to my stomach after one bite. I end up being unable to eat for a while, if not the whole day.

That's really bad.

Try and make your 3 major meals smaller and have healthy snacks more often to encourage your body to keep burning calories. iirc having certain types of tea in the morning help boost your metabolism, but tea is generally pretty good to have anyway.