Recently I Have Noticed That I Am Extremely Fatigued, Have

Recently I have noticed that I am extremely fatigued, have more shortness of breath even without strenuous activities or even just walking upstairs, weight gain, severe swelling of my ankles and feet. I have gained a lot of weight (35 to 40) and have no energy to do anything. Also, I have been put on stimulants (Addaroll) but they do not affect me at all (nor does any stimulants such as coffee, energy drinks or pills), what is wrong with me?