Hello, I Have Been Suffering From Constant Fatigue And Brain

Hello,
I have been suffering from constant fatigue and brain fog for quite some time. Along with previously mentioned I feel a constant pressure around my forehead. I also have a hard time sleeping. Sometimes due to too much on my mind or sometimes I will be sleepy, go to bed then be wide awake. I was wondering if this is any signs of diabetes, or diet related. I workout 5-6 days a week and feel great after, but the symptoms come back after a couple hours. Any direction would be great.