Doctor says I have reactive lymph nodes. What does this mean? Is it cancer? I get panic attacks, chronic nausea, headaches, ear ache, chest aches.

Benign. Reactive lymph nodes are by definition benign, and not themselves the site of any illness. You're dealing with many somatic issues, and especially in your traditional society, you have a duty to ask your physician exactly what is going on with your health, while you are in the office. Don't leave until all your questions are answered. You have a right, anywhere in the world, to accurate info.