I'm thinking you may have a type of migraine. Have you been to see a neurologist yet? If your blood sugar and blood pressure are normal I would think about seeing a migraine specialist (neurologist). I was diagnosed in my 20's with migraine variant. All I had was throwing up at night. It wasn't every night though but only at night. It seemed to be related to excitement or stress. But different things can trigger a migraine and also you can have daily migraines. So, they did an electroencephalogram (EEG) on me and I was positive. They just attach wires to the outside of your head or you wear a cap and they measure the electrical part of the brain activity. The other thing would be to get a CT scan or check your inner ear by an ENT. I had that done more recently because I got severe vertigo and was falling over. It wasn't related to movement. They wanted to rule out meniers disease so they did a hearing test, and looked at the ear and then the symptoms told them that it was more related to my migraines. So, I added a new med for my migraines and it is working. The CT was to rule out an acoustic neuroma behind the ear. I didn't have that either. It is best to go through the motions to get these things ruled out when you have dizziness. I guess the big question is do you get dizzy when you move to the side? If you do then it is benign positional vertigo. But you don't see the room spin it is just dizziness?
Have you bee checked for diabetes and do you east regularly?