Diet help!

So last summer I weighed in at about 230 pounds. Though a multitude of Diets, cuts, and exercise, I have successfully dropped to about 140 pounds. I'm trying to gain muscle mass to make my body look better, but I'm having a hard time. I know you're supposed to eat quite a bit of protein, and calories in general to build muscle, but every time I eat more, I gain weight fast. I assume this is because my body is very used to only eating 1400 calories on average per day. How should I get my calories to the right amount to gain muscle, without gaining fat?