I am stuck in this beta version in my windows 10 pc

I am not enrolled in the beta  in the xbox insider app

I want to go back to the current version but am not able to

Do you guys have any fixes 

And another problem is when i launch minecraft it opens shows a white screen and closes(In 1.15.0.8)

It used to run fine in the previous version and could  play properly without any issues.

I have already tried uninstalling it and installing it back but it did not work.

Pls Help Me

"HIGH PRIORITY"