Hi there,
I think most of us here can say that we know what you are talking about. When we are under a lot of stress, all of our body parts are affected. The feeling you are describing is probably just your scalap muscles becoming tense and is almost definitely not a brain tumor. I get this feeling too. In Claire Weekes book, Hope and Help for Your Nerves, she explains it this way:
"The soreness around or on top of your head is caused by contraction of your scalp muscles as a result of continuous tension. You may notice how relief comes if you press your scalp or place a hot-water bag where it is most sore. This should prove to you that the cause is local, where you can reach it, and is not deep-seated. These are not the symptoms of brain tumor. Since contraction of tense muscle causes pain, it naturally becomes worse when you worry and improves as you relax and release tension."
Hope it helped,
Jen