I think it's trial and error. Although there are calculations to tell you how much you should be eating, these are only general guidelines. Each individual is different- metabolism, age, calorie burning. 1800/1900 calories may not seem to be too much, but at that rate, I would gain at least a pound a week. So I have to keep my calories much lower, with a cheat day here and there.
Also, I have found that the 3500 calories per pound marker does not translate equally in real life. Theoretically, it works, but individual differences interfere.
Just make sure you are taking in good quality healthy foods. Try adjusting your calorie intake for a week or two and see what happens. You can't wreck your metabolism in just a few weeks.
If we didn't have any life at all, extreme exercise would work. Even though I don't work at a job any more, I still have things I like to do. So trips to the gym are only one part of my day.
Try adjusting your workout routine (as well as the calories). Maybe you need to bust through a plateau.
Hope this helps...
Do or don't do; there is no try (Yoda)