2cm swollen left submandibular gland for 6 months following throat infection.health is fine and blood tests are fine, should i worry? is it lymphoma?

Unlikely: You may wait and watch. Check the glands once every two weeks or so. If the gland more than doubles in size, becomes painful, additional glands become large, you develop fever, lose weight, or if the gland ulcerates, it would be time to see your doctor. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex. Get HPV vaccine.