hello and welcome to HCM forum,
According to the history provided here i will provide you with the best possible answer,
Following extraction, a wound is formed at the site, it undergoes healing on its own and takes about 10 -15 days.
I appreciate that you are following the instructions given by your dentist
The blood clot gradually undergoes fibrosis
which gives it white color.
For the sensitivity i will advise you to see your dentist , he/she might prescribe some anti-sensitivity tooth paste.
Do not worry you will be fine a few weeks,
remember to maintain proper oral hygiene
i hope this answer was useful,
i wish you good health