Don't give up US citizenship yet. You are going to miss out social security benefits etc. But from Feb 1 , you can get NRN card online if you want to stay in Nepal. Check the link below. Also, new Nepali president can pass the dual citizenship law for non- saarc countries. This law was almost passed last time. NRN folks need to pressure our government. You can always renounce your US citizenship.

https://us.nepalembassy.gov.np/nrn-id/