Can hearing loss in the left ear be a punishment for watching forbidden movies for which one has repented? And how can someone who watches movies repent to God? Does repeated viewing deprive one of Paradise?

The affliction that has befallen you is a divine decree from Allah, for a profound wisdom. Your patience and contentment with it will greatly magnify your reward. It might be due to a sin you committed, or it might be for you to attain a higher station with Allah. Your duty is to be patient and content with Allah's decree, recalling His saying: "No disaster strikes except by permission of Allah. And whoever believes in Allah - He will guide his heart." As for the films you mentioned that you regret watching, one who repents from a sin is like one who has committed no sin. So, continue steadfastly in your repentance. Allah is Oft-Forgiving, Most Merciful, and He will not deprive a believer of Paradise because of a sin if he repents from it. The conditions for repentance are: abandoning the sin, resolving not to return to it, and regretting having committed it.