I have myopia with an eye power of -5. In this pandemic, I am working for six to seven hours on electronic devices. I have mild headaches on and off. It comes and goes on its own at any time. I also have drowsiness and sometimes, I also have heaviness in my head with a problem of slight blurred vision. I am worried about my condition and I want to know whether I have a brain tumor or some other issue. Kindly help.