No one expects you to be perfect.
No one expects you not to make mistakes.
But it is only a problem if you do not learn from your mistakes.

You can't stop yourself from making mistakes.
When it happens, learn from it. 
But try not to make the same mistakes again.

If you want to learn, if you want to grow, 
strive to make more mistakes. 

Do not let mistakes stop you from enjoying your learning.
If you care so much about what you are doing, 
if you love what you are doing, 
you will strive to do whatever 
it takes to make it happen, including making mistakes.

Stop trying to stop what you can never stop. 
It is a waste of time to try to avoid mistakes.
If you do, you are cheating yourself.