Rigidbody regenerated acceleration movement ?

Hello , i'm trying to move my player like cars so when i move i speed up from zero to max speed and i want so when i hit a wall and turn away i regenerate my speed again like cars games.

I tried adding force but it keeps adding force and when i rotate the player it's like icy movement.

One more thing i don't want my player to go through walls.

Thanks for any help.