sprite and tile map COLLISION problem?

[ScavaJripter]

So my game, ( http://narric.com/underdog_football/ ), has this problem where i go through the tile map when I fall from high spots or if i jump up with high velocity. I have the gravity really high, when i lower it there is no problem, BUT I WANT THE GRAVITY HIGH!  I don't think its a problem with the tile map because there is no problem when i lower the gravity and jump velocity.

The code below isnt all the code for the game. (I normally have "preload" in another .js file and i got rid of the code for the intro screen and there is a boot file thats not included). I'm new to phaser and coding in general so any help is appreciated.

var game = new Phaser.Game(1152,672, Phaser.AUTO, 'game_div');preload: function() {		this.load.image('box', 'images/box.png'); // loading the tileset image                this.load.tilemap('boxy', 'images/boxy.json', null, Phaser.Tilemap.TILED_JSON);		this.load.spritesheet('player', 'images/football_sprite20.png',72,132,20);	},create: function() {        this.physics.startSystem(Phaser.Physics.ARCADE);	map = this.add.tilemap('boxy'); // Preloaded tilemap        map.addTilesetImage('box'); // Preloaded tileset        layer = map.createLayer('Tile Layer 1');         layer.resizeWorld();        map.setCollisionBetween(0, 1);        this.player = this.add.sprite(100, 100, 'player');	this.player.anchor.setTo(.5, 1);	this.player.animations.add('walking', [0,1,2,3,4,5,6,7], 18, true);	this.player.animations.add('sprinting', [12,13,14,15,16,17,18,19], 25, true);	this.player.animations.add('jumping', [11], false);	this.player.animations.add('idle', [8,9,10,9], 4, true);	this.physics.arcade.enableBody(this.player);	this.player.body.collideWorldBounds = true;	this.player.body.bounce.y = 0.05;	this.player.body.gravity.y = 5000;	this.player.scale.x = 1;	this.player.scale.y = 1;	cursors = this.input.keyboard.createCursorKeys();	jumpButton = this.input.keyboard.addKey(Phaser.Keyboard.SPACEBAR);},update: function() {		this.physics.arcade.collide(this.player, layer);		this.player.body.velocity.x = 0;               //====JUMPING====		jumpButton.onDown.add(jumpAction, this);				function jumpAction(){			if (this.player.body.onFloor()) {					this.player.body.velocity.y = -1400;					this.player.body.gravity.y = 5000;			 		this.player.animations.play('jumping');			 		                                        if (cursors.down.isDown || sKey.isDown) {						this.player.body.velocity.y = -1800;						this.player.body.gravity.y = 5500;					}				}		}		//====MOVING LEFT====		if (cursors.left.isDown) {			this.player.body.velocity.x = -500;			this.player.scale.x = -1;			this.player.scale.y = 1;			if (cursors.down.isDown && this.player.body.onFloor()) {					this.player.body.velocity.x = -730;					this.player.animations.play('sprinting');				}			else if(this.player.body.onFloor()){					this.player.animations.play('walking');			}		}		//====MOVING RIGHT====		else if (cursors.right.isDown) {			this.player.body.velocity.x = 500;			this.player.scale.x = 1;			this.player.scale.y = 1;						if (cursors.down.isDown && this.player.body.onFloor()) {					this.player.body.velocity.x = 730;					this.player.animations.play('sprinting');				}			else if(this.player.body.onFloor()){					this.player.animations.play('walking');			}			}		//====STANDING IDLE====		else if(this.player.body.onFloor()){			this.player.animations.play('idle');		}	}};