Your allergy medicine is probably an antihistamine. If the ringing is cause by unequal pressure in your ears, those won't help, but a decongestant will. If you're absolutely sure that isn't the problem, then you need to see a doctor.
I have to ask, do you use the nasal spray every day? Long term use (more than a few days) can cause serious damage to the lining of your nasal passages. Make sure you mention that to the doctor.