Hi Mark, I would always seek a second opinion and get a needle aspiration biopsy. Then you can know why your nodes are swollen. Knowledge is power and knowing releives stress because no matter what the causes are you are taking care of yourself.
After my husband's surgery, I also found a lump in my body. It was just a cyst but I worried when ever I felt it so I went for a second opinion from a repudable specialist which put me at peace. I can check it a couple times a year but I am not worried anymore. I waited about a year in my case because I knew my case was not an emergency and I didn't want to take someone else's spot.
In your case you should book your apointment to be seen as soon as posible, then seek some help to deal with your anxiety. My husband and I saw someone after his treatment and my doctor helped me with my anxiety. When we first found out about his cancer I needed a little medical help for stress, but I only used this a few times while I was having a panic attack.
There is great help out there, the greatest thing my doctor said to me when I worried that Stephen's cancer would return was, "who are you to take away the life he has with your worry? Be there for him and live the life you both have" "No matter what happens, he deserve to live his life fully, and if you take it away with worry while he is a surviver, isn't that a wast"? "Celebrate, love and live while you can".
This was my family doctor's words and it woke me out of a dark dark deepening tunnel.
Keep positive, Sophie