Brief Answer:
Read below.

Detailed Answer:
I read your question carefully and I understand your concern.

There are two main possibilities to your episode of sudden loss of balance.

One possibility is an inner ear origin. The inner ear is very much involved in balance and issues such as crystals displacement in its inner canals, infections etc may lead to balance issues. If the loss of balance was in the form of vertigo, spinning sensation that is more likely. Even more likely if also any symptoms such as abnormal sensations or sounds in the ear.

The other possibility would be a TIA, transient ischemic attack, a transitory neurological deficit due to the temporary blockage of a blood vessel. The problem with TIA is that they may indicate a risk of having a stroke. It generally happens in the early months though, so the fact you had another episode 2 years ago is reassuring. However if you manifest any other symptom such as double vision, weakness of the limbs on one side, loss of sensation in half the body and/or face, movement coordination issues, headache, vomiting or even the same loss of balance, do not hesitate to be taken immediately to the ER, because may be signs of stroke and early treatment is vital in avoiding stroke consequences.

I remain at your disposal for other questions.

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