Having some issues with my Animator Controller.

So I'm working on an Over world for my Turn based Role Playing Game, and it's going kind of well, but I've hit a roadblock at the animations phase. So I have 4 different animations, a frontIdle, backIdle, frontWalk, and backWalk. Here's my script for the animator Controller. The issue i'm having is that it just won't connect I guess? I have the script linked to my player object, along with the animator Controller, but whenever I test it, he just kind of floats around in his idle animation, which is the sprite renderer sprite as well. please keep in mind this is my first submission to the forums as well as my first attempt at a game in general, so some soft criticisms would be appreciated!

 public class PlayerControllerOverworld : MonoBehaviour 
 {
     
     public float walkSpeed = 1; // player left right walk speed
     private bool _isFront = true; //check to see if player is facing front
     
     Animator animator;
     
     //some flags to check when certain animations are playing
 
     //bool _isPlaying_walk = false;
 
     
     //animation states - the values in the animator conditions
     const int STATE_IDLE = 0;
     const int STATE_WALK = 1;
     const int STATE_BACKWALK = 2;
     const int STATE_BACKIDLE = 3;
 
 
     const int FRONT = 0;
     const int BACK = 1;
 
     
     string _currentDirection = "right";
     int _currentAnimationState = STATE_IDLE;
     int _currentFrontOrBack = FRONT;
     // Use this for initialization
     void Start () 
     {
         //define the animator attached to the player
         animator = this.GetComponent<Animator>();
     }
     
     // FixedUpdate is used insead of Update to better handle the physics based jump
     void FixedUpdate()
     {
         //Check for keyboard input
         if (Input.GetKey ("right"))
         {
             changeDirection ("right");
             transform.Translate(Vector3.right * walkSpeed * Time.deltaTime * 3);
             
             if(_isFront == true)
                 changeState(STATE_WALK);
             else if(_isFront == false)
                 changeState(STATE_BACKWALK);
             
         }
 
         else if (Input.GetKey ("left"))
         {
             changeDirection ("left");
             transform.Translate(Vector3.right * walkSpeed * Time.deltaTime * 3);
             
             if(_isFront == true)
                 changeState(STATE_WALK);
             else if(_isFront == false)
                 changeState(STATE_BACKWALK);
             
         }
 
         else if (Input.GetKey ("up"))
         {
             transform.Translate(Vector3.up * walkSpeed * Time.deltaTime * 3);
             _isFront = false;
 
             if(_isFront == false)
                     changeState(STATE_BACKWALK);
         }
 
         else if (Input.GetKey ("down"))
         {
             transform.Translate(Vector3.down * walkSpeed * Time.deltaTime * 3);
             _isFront = true;
             if(_isFront == true)
                 changeState(STATE_WALK);
         }
 
         else
         {
             if(_isFront == true)
                 changeState(STATE_IDLE);
             else if (_isFront == false)
                 changeState(STATE_BACKIDLE);
         }
     }
 
 
     //--------------------------------------
     // Change the players animation state
     //--------------------------------------
     void changeState(int state){
         
         if (_currentAnimationState == state)
             return;
         
         switch (state) {
             
         case STATE_WALK:
             animator.SetInteger ("state", STATE_WALK);
             break;
 
         case STATE_IDLE:
             animator.SetInteger ("state", STATE_IDLE);
             break;
 
         case STATE_BACKWALK:
             animator.SetInteger ("state", STATE_BACKWALK);
             break;
 
         case STATE_BACKIDLE:
             animator.SetInteger ("state", STATE_BACKIDLE);
             break;
 
             
         }
         
         _currentAnimationState = state;
     }
 
 
     void changeBackOrFront(int backOrFront){
         
         if (_currentFrontOrBack == backOrFront)
             return;
         
         switch (backOrFront) {
             
         case STATE_WALK:
             animator.SetInteger ("backOrFront", FRONT);
             break;
             
         case STATE_IDLE:
             animator.SetInteger ("backOrFront", FRONT);
             break;
             
         case STATE_BACKWALK:
             animator.SetInteger ("backOrFront", BACK);
             break;
             
         case STATE_BACKIDLE:
             animator.SetInteger ("backOrFront", BACK);
             break;
             
             
         }
         
         _currentFrontOrBack = backOrFront;
     }
     
     //--------------------------------------
     // Check if player has collided with the floor
     //--------------------------------------
     void OnCollisionEnter2D(Collision2D coll)
     {
         if (coll.gameObject.name == "Floor")
         {
             _isFront = true;
             changeState(STATE_IDLE);
             
         }
         if (coll.gameObject.name == "WallLeft")
         {
             _isFront = true;
             changeState(STATE_IDLE);
             
         }
         if (coll.gameObject.name == "WallRight")
         {
             _isFront = true;
             changeState(STATE_IDLE);
             
         }
         if (coll.gameObject.name == "Roof")
         {
             _isFront = true;
             changeState(STATE_IDLE);
             
         }
 
         
     }
 
     //--------------------------------------
     // Flip player sprite for left/right walking
     //--------------------------------------
     void changeDirection(string direction)
     {
         
         if (_currentDirection != direction)
         {
             if (direction == "right")
             {
                 transform.Rotate (0, 180, 0);
                 _currentDirection = "right";
             }
             else if (direction == "left")
             {
                 transform.Rotate (0, -180, 0);
                 _currentDirection = "left";
             }
         }
         
     }
 
 
 
 }