1800 calories holy **** that's insane! I try to eat 3000+ calories. Imo, what you eat is more important than how much. I'm not a nutritionist or trainer or anything, but my hypothesis is that eating less food (especially junk food) kinda tells your body to slow the heck down and conserve what little nutrition it is getting.

Good news is you are almost at your goal weight and don't have to feel guilty eating a more sane amount of food!