I prefer to give you advice regarding food . To increase omega 3 intake , use olive oil, mustard oil rice bran oil for cooking . Eat flax seeds,nuts like almonds, walnut cashewnuts etc.
Next Steps
exercise and eating balanced diet include all green leafy vegetables, dark and red yellow color vegetable and fruits.
Health Tips
For your immunity you need zinc, Selenium, amino acids, vitamins like A C E and D and many other nutrients besides Omega3, So better to eat healthy food and not waste money..you can consult me on practo for a personalized diet.