Can you be worried an anxious about something without knowing it and then can it cause dizziness or a small anxiety attack?

Yes: All of us have unconscious ways of protecting ourselves from emotional pain. This often means stuffing distressing situations & emotions deep inside us, so we're not consciously thinking about them. The anxiety may build, though -- and has to express somehow. Our bodies provide physical outlets for these energies. It's only temporary, since we get anxious about the physical symptoms too!