Hello and welcome to the forum. Thanks for your question, we appreciate it. Snoring is a common problem and there are some symptoms that can indicate sleep apnea. These include things like if you are tired during the day, you have a sore throat in the morning, you are restless at night, you have any chest pain, high blood pressure, etc. Those warrant doctor care right away to examine if sleep apnea is occurring and to begin treating it. https://www.mayoclinic.org/diseases-conditions/snoring/symptoms-causes/syc-20377694 However, most definitely a chronic nasal drip can cause snoring.
Is your chronic post nasal drip related to allergies? It often is but there is also non allergic chronic rhinitis. I would recommend seeing an ENT to discuss possible solutions to either alleviate this issue or improve it. They may look at other things that could contribute such as your anatomy of the nose and throat as well as if you have GERD or anything like that. Sometimes an air purifier helps and dry air makes it worse so hopefully it helps for you to use a humidifier. There are a number of different medications indicated to treat this as well. https://www.medicinenet.com/chronic_rhinitis/article.htm
Seeing an ENT would be really helpful for you and we hope you come back and let us know how it is going.