help for reset axis value for mouse .

Hello everyone i try to make a classic horror game like classic RE series and unfortunately i have a bad problem which i don’t know how should i fix it , the problem is i made aim for my character and my character controller is like classic RE and i need to reset the aim after releasing aim bottom but every time i used aim for up or down it will stuck on that angle and next time when i aim instead of default aim center it will start from aim up or down and i need to know that how can i fix this , i try to set mouse pitch axis value to 0 but it seems there is not any blue print node for it or at least i don’t know how to set it .
i will be appreciate for any help and thanks in advance .
you can look at the video below .