Brief Answer:
Read below.

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

Dizziness can be due to many different causes, its description as well may vary among patients, they use the word to describe different sensations. One of the most common causes are ear issues such as Meniere's disease, vestibular neuritis, labyrinthitis etc. In this case usually dizziness presents in the form of vertigo, a spinning sensation. An infection might well be the case given your upper airway issues.

Apart from vertigo it can also present in the form of an off-balance sensation. That may be due to other issues such as cervical spine issues, probable if accompanied with pain or muscle spasms in the back of the neck and head.
Stroke might also be a cause for that but generally there are other symptoms such as headache, vomiting, weakness or numbness of the limbs on one side, sensation changes over one half of the body, vision or eye movement abnormalities etc, so unlikely.

Other causes might include heart arhythmia, blood pressure changes, anemia etc.

So if in the form of vertigo, I suggest a visit to an ENT (ear-nose-throat) specialist given also your other recent troubles with laryngitis and sinusitis. In the meantime you can use a antihistaminic like meclizine to alleviate symptoms.
If you have other signs like those I mentioned which could indicate a stroke you should head to the ER instead to exclude that.
If not getting better you should check also with your primary physician for some routine blood tests like blood count, inflammation tests, biochemical panel, to search for indication of anemia, infection or metabolic changes, as well as monitor blood pressure and heart rate.

I remain at your disposal for other questions.

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Brief Answer:
You're welcome

Detailed Answer:
I hope you will feel better soon.

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