Why I am unable to unstake my cosmos from my trust wallet?

please help me unstake my cosmos and withdraw from wallet.

Unstaking once started takes 21 days before the tokens become transferrable.
Here is a guide that explains it further.
https://community.trustwallet.com/t/how-to-unstake-cosmos-atom-tokens/188/2

Is there a way to stop the unstake process?

No way to stop it once it has started.