Health issue, Sugar Related Problem, Need Advice, What can help?

I had a headache every day for about 2 weeks. It was to the point where my vision was blury and it felt like a giant hangover all the time. I have new insurance so I went to this Dr. For the first time and he tells me straight up that I have a brain tumor! I'm 25 years old Female. I went, had a CT scan chest x-ray and bloodwork. Waited days for the test and he said I was fine. I myself decided to cut out all sugar. I asked him if it was a sugar problem first and he said no way. After I cut out all sugar I was fine! Not grat but waaaay better. Everyonce and a while I get sick. Any adive. The Dr. around here arnt very good. Should I get a blood sugar tester from the store? I was taking Chronimum? And that helped a little. If having sugar makes me sick what kind of sugar problem is that? I was hyperglysemic when I was little, not having enough, I'd have to eat. Any advice would help, just dont say go the th dr. I spent 700+ of my own money and still not one said I have a sugar problem!