handling player impact in a proper way

hi i have a quite a complicated question for me at least . in my player controller class i use unity's characterController component to move the player based of the input i give it to it and multiply it with speed and add the gravity like this

         CurrentImpact = vector3.lerp(CurrentImpact,vector3.zero, damping * Time.DeltaTime) 
         velocity = InputDirection();
         velocity *= Speed();
         velocity += Gravity;
         velocity += CurrentImpact;
         CharcerController.move(velocity  * Time.deltatime)

my problem is with CurrentImpact. CurrentImpact is a vector3 that i use to add force to the player like jumping and pushing the player around put if i do like adding a force facing left maybe and the player is trying to move right, the player will go right then will start drifting a little bit on the left again so what i think i want is a way to make the CurrentImpact Face the direction of the input movement if its weaker than it without changing its magnitude.

i hope you understand me and thanks