As in the days before Covid, the Non Immigrant B visa can only be Extended on basis of working in Thailand with Work Permit. As soon as the jobs stops, there is no reason to be inside Thailand. Only option is to go abroad and get a new type of visa.
Amazing, complaining about Thai Immigration because you are unable to decide which visa fits your purpose of stay and all Immigration does, is giving you 60 days longer to think about how to solve your problems. Remember all countries are opening up and flying around gets more easy every day.
Talk to the people who placed you in quarantine and tell them your immigration status. They can make a letter and collect your passport and fees to apply in your name for an Extension of Stay, but it must be done today.
Wrong, even if you lived in Thailand for years, you have to meet the requirements to convert the tourist visa or visa exempt entry into a Non Immigrant O visa.