I take Allegra (fexofenadine) in morning 180, but allergy hit me at night while am sleeping, should I take another bill at night?

You can but... You can take Allegra 180mg twice a day or you can take a Benadryl (diphenhydramine) at night instead. If you require frequent OTC antihistamine dosing throughout the day you might want to talk to an Allergist for further workup and evaluation as there are other treatment options including nasal sprays that can be helpful and reduce symptoms better than Allegra can.