Brief Answer:
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Detailed Answer:
Googling symptoms can sometimes help provide information if you already know your diagnosis but when trying to self diagnose, usually it just frightens people because it won't say what is most likely.

The most common cause for what you are describing is eustachian tube dysfunction and possibly serous otitis. Eustachian tube dysfunction can happen when there is drainage in the throat due to allergies or a cold and it causes pressure changes and sometimes (clear, uninfected) fluid behind the ear drum. This causes a number of symptoms. The plugged feeling is due to the ear drum not moving well because it is sucked inward somewhat from the pressure abnormality in the eustachian tube, or from fluid behind the ear drum. Hearing one's heart beat is not uncommon and it may be somewhat amplified.

If it is annoying of doesn't go away, then I recommend going in to a doctor who can look at the ear drum and check it's movement with an air puff that can be done through the otoscope.

Any sound you hear that isn't coming from the outside world is called tinnitus.

Ménière's disease can cause dizziness and balance problems, and loss of hearing. It would not be something to diagnose by looking up but rather by seeing an ENT specialist in person. It would require an exam. If you have a cold though, or fluid in the ear, that can cause light headedness too.

I hope this information helps. Please let me know if I can provide further information or clarification.

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Brief Answer:
Information

Detailed Answer:
Fluid behind the ear drum can continue for some time after a respiratory illness has resolved. That may be what is going on.

If you think you may have punctured your ear drum with the qtip from accidentally jabbing it, then you must go to get it checked.

If there is fluid behind the ear drum it can cause symptoms of dizziness.

If the dizziness worsens then do go in to get it checked, but most likely this is a residual symptom from the previous infection.

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