Hon I have been there before. A few years ago I went through the IBC fear. For weeks I had real genuine pain in my one breast. It really hurt. Eventually I decided that if I had IBC I would have seen something on my breast by then, it would have looked swollen and inflamed. As soon as I realised this, the pain eased and eventually went away.
I have been down the lymphoma path too. I drove myself crazy. I developed itching on my leg, pain behind my knee, lower back pain. The pain and itching were real. But not caused by lymphoma.
The human mind is very strong. It is proven that when you focus on something in the body, you highlight it. The pain and itching you feel are real, but the cause is not cancer. If you can switch your mind off for a few hours; engage in life, watch a good movie, play a board game, have a great conversation. I think you'll be surprised at how quickly the symptoms lessen. As I said, just try this for two weeks and if no improvement then get it checked out. Either way though you should try not to worry, these are not highly concerning symptoms.
To answer your question: Your worrying may or may not have caused these symptoms to come. But it is DEFINITELY making them more apparent to you and therefore making them worse. Nothing is seriously wrong with you.