Since your current O-A Visa that you have is still good until sometime in Jan 2021.
If you could get into Thailand 45 days or more before it Expires - then you could go to Thai Immigration and apply for a one year Extension of Stay. You technically need proof of 800,000 Baht in a Thai Bank two months prior to applying... But considering Covid Lockdown problems they might be forgiving of the two months Seasoning. You would have to have the Health Insurance and the Specific Covid-19 Insurance. Both a bit expensive. Plus 10 to 14 days in a quarantine hotel (expensive)
Another way to do it... But probably better to wait until Feb / Mar - get a new O-A - with luck some of the barriers may be lessened
The United States of America is known world wide as "America". If you don't like that - then too bad.
Example - Ask a Thai person if they know about the United States. 9 out of 10 times you will get a strange look. Ask a Thai about America (Ah-Mar-E-Kha. They will know exactly what you're talking about.
In the first year of the O-A Visa - the Visa is Multi-Entry with unlimited exits and entries back into Thailand. No reentry stamps are needed. If you really have an O-A Visa and are in the first year