Well, just one night’s use of ear plugs is unlikely to cause any hearing loss. However, it can block or change pressure in the Eustachian tube (connecting inner ear to throat). Try valsalva maneuver (take a deep breath and blow while pinching your nostrils shut and closing your mouth). This may help open up the ear.
If you have wax or infection in ear, then using an ear plug can aggravate it. Also, yes, prolonged use of ear plugs may also cause some hearing loss. If the problem persists, please see a doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.