No matter what I do, I cannot lose weight. I keep going up, and up, and up. My thyroid has been checked- all is good. This has been happening for almost 4 years now

I had lost over 80 pounds several years ago, kept it off, got pregnant with my fifth child and then gained it almost all back. I am now a mere 5 pounds away from that original 80. It has been severely depressing. When I first went to my doctor almost 4 years ago about gaining, he told me, "it's because you are now 30, eat less, exercise more." I told him I can't eat less, I'm starving now! To which his response is still, cut back more

I am now eating barely 1,500 calories a day and am moderately active. Anyone else in this boat? If I eat ONE calorie over (okay, in reality, if I treat myself with a cookie about 65 calories), I kid you not, the next day the scale is up between 2-3 pounds and it STAYS...