Who diagnosed this as lymph node?
Have you had any scans?
What is your height and weight?
What is your clothes size, is this US or UK measurement?
Have you had any tests?
At your height then weight increase will have a significant effect on how you feel. Increased abdominal weight often makes people feel tired and causes shortness of breath.
The first thing is to keep a detailed diet record for the next two weeks. If you are managing to keep your calories at 1200 daily and you can fit in some exercise every day then you should start to see a weight loss of about 2 pounds per week. If you are eating less than this, and continue to put weight on then that would require additional tests
If you have been sexually active then it is worth doing a pregnancy test too.
At your age, serious causes of ankle swelling are rare but you should ask your doctor to check your kidney function and if you have developed purple stretch marks then perhaps also consider a cortisol test too.