Nito, you contacted me about the use of a nasal spray you are using. I'm going to reply on the forum because we have other members that can help you, and be helped by this information.
Oximetazoline, also in Afrin, should not be used for extended congestion relief because you become dependent on it, and it causes rebound congestion. Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays). It is more than likely that your congestion is the result of using this spray, not humidity, and now you are facing the need to withdraw from this addiction.
https://en.wikipedia.org/wiki/Rhinitis_medicamentosa
Withdrawal is difficult. Some people are able to quit immediately, others use a slower withdrawal or one nostril at a time. It won't be much fun, but you must stop using this drug. Get saline drops to help, read information online, and get informed. Nasal pillows will help keep your sinuses open much better, consider getting them.
Good luck, and don't hesitate to consult the forum for help. This is not going to be easy.