Need meat on my bones Help Help Help

What height are you? And are you male or female? How many calories do you eat and burn in a day?

If your weight remains the same then you are eating at maintenance which means that you are eating the same amount you burn.
You need to slowly increase your calories. May be add in a few tablespoons of peanut butter extra a day or something high calories to boost it.

Do you know how many calories you are eating now? Have you started tracking? How active are you outside of exercise and do you exercise? What kind of foods do you eat?

Overall, gaining weight is not that hard, you just have to be willing to eat higher calorie foods. Where most people get in trouble, is they teach themselves to eat a lot of diet or low calorie foods and push off the higher calorie items. If you are currently maintaining, it might be beneficial to just add one more meal on top of your current program. So if you normally eat 3 meals, throw in a high calorie snack. Or just track what you eat and replace low calorie foods with high calorie foods. Lots of ways to do this.