Hello, as per the details mentioned by you and the dentist you should get the grossly decayed rootstumps in the upper arch extracted. And for lower teeth caries get x-ray done based on that get them filled or root canal treated. Dont wait and get the lower teeth treated on time else they will also go for extraction.
Next Steps
Extraction of upper teeth
Xray of lower teeth
Health Tips
Visit the dentist and get the treatment started and you will be fine.