Hi and thanks for the query,
Pain in the ears can be caused by a variety of causes, most common being infection.
Clogged sensation of the ears can be caused by infection or by accumulated wax.
Since you did have a sinus infection
last week the chances of infection are high,
please consult a doctor for the same.
You can take over the counter pain killers after checking the dosage.
If you scream in your babay sister's ear there will be no harm to your ear, but your sister may experience pain and ringing, nothing really serious.