Dizziness

I have been experiencing dizziness since just before Christmas. At first I just thought it was from the sinus medication I was taking. So I stopped taking it. I've still been experiencing dizziness. I told my parents and they said it could be fluid in my ears. I know what that feels like and it doesn't seem like that's it either. I read something that said dizziness can be a symptom of the following: low blood sugar, high blood pressure, flu, blood loss, hypothyroidism, anemia, and pregnancy. I'm sure I'm not anemic or that I have hypo or hyperthyroidism because I just had a wellness check at work and they did blood work that showed everything was normal. I doubt I have the flu because nothing else is really taking place if you know what I mean. I also don't think it's low blood sugar because I've been trying to eat every 3 hours just to be sure of that and my blood pressure was taken on Sat. and it was excellent. So... there's like one option left other than blood loss which isn't happening either. I've also been extremely tired... as in I could doze off at any moment and it doesn't matter if I had a great night's sleep or not. There is the possibility that I could be pregnant. I don't think I am... The only symptoms I have are extreme fatigue and then dizziness. Has anyone else experienced this before? It's just really frustrating to feel like this all the time and I'm afraid it might happen while I'm driving or something.