[Concern] Discomfort at the back of the nose and post-nasal drip

I have had rhinitis since a long time ago, but once I became an adult, it improved to the point that it was not severe anymore.

The problem suddenly appeared as post-nasal dripㅠㅠ At first, I didn't even realize it was post-nasal drip and just went to the hospital blindly, but the doctor said, "Aren't you just thinking that way?" haha.. I found out later that the doctor at that hospital was a notorious quack and a temperamental doctor known for being unprofessional.

At the time, I didn't know about that, so I thought, "Oh, I'm just being sensitive," and I just thought I should drink a lot of water.

I went to another hospital because of a cold, just in case, and when I asked about the symptoms, they said it was post-nasal drip.

I often think that I wish I had known a little earlier.

I took my medication for a moment, but I was told not to habitually inhale through my nose.

Since this comes over my nose, I unconsciously inhale through my nose and exhale through my mouth, causing discomfort ㅠㅠㅠ

Is there anyone who knows a good way to treat post-nasal drip, which is a habit I really want to fix?