Your permanent residency is Chinese Visa permanent residency?
If you're a citizen of a foreign country - then as @lemon noted - visit the Chinese consulate to update your residency status - don't wait too long, start the process about a year in advance, as you'll need lots of documentation, authentications, apostilles (depending on country of citizenship).
As you were born in Kunming and probably have a birth certificate to at least one Chinese national parent, you are eligible for Chinese citizenship, if you so desire, until the age of 18yo. You'll have to check the Chinese embassy/consulate website (which may not always be up to date) and immigration/visa law.
Here's weblinks for the Embassy and the Consulate of China in the USA, for convenience:
There's NO need to do keep alive visits at embassies or consulates.
The Chinese versions of these websites will have more information for Chinese citizens living abroad, which you may want to check, if you can read the websites.
You may also retain the services of an immigration and visa attorney or travel agency, but suggest you do research yourself first, so you are reasonably familiar with the answers, before you ask the questions. A savvy consumer is a wise(r) consumer.
Good luck - the city has changed a LOT since you left, with constant construction of new mega real estate developments.
Finally - no need to be ashamed. If you ever visit the Kunming Visa Entry/Exit office - you'll see it crowded with Chinese citizens and local Kunming people navigating the legal frameworks of passports, entry & exit, for the first time.
Welcome home - please have a safe and enjoyable visit with family and perhaps new friends.