Adrenal issues can contribute to weight gain through a few means. Cortisol release can release stored glycogen from the liver leading to an increase in serum glucose. This leads to a release of insulin, which in turn stimulates the formation of body fat. It can also lead to water retention through aldosterone. And adrenal dysfunction can lead to hypothyroidism. Although weight gain has a variety of other causes.
Because you have known adrenal issues I would focus on the adrenals first. If this does not take care of the weight issue then I can give you other suggestions later depending on what other causes are likely. Although, one thing you can do in the meantime is to add watercress to your regime. This is not only a good source of vitamin C, but it is also rich in other nutrients, will help get rid of excess water, helps the thyroid, and is a thermogenic thereby helping to burn body fat.