dealing with different screen sizes in xcode

I have an iPhone game that was first developed for iPhone 6 and when played on the iPhone 5 sim it works fine but when played on the iPhone 4 sim the sides are stretched out?!? and the nodes that I spawn in from the left and the right side spawn on the screen instead of off the screen like on the iPhone 6 and 5. (please don't say this is a duplicate as I have been looking for weeks of how to deal with different iPhones)

I have arrows coming in the from the left and the right that spawn randomly on the y axis. They spawn off screen then slowly move on screen than move quickly across the screen but on the iPhone 4 the arrows spawn on the screen. this is the code for one of the arrows

-(void) leftArrow
{
    int randomY = arc4random() % (675 - 175);
    int yPoint = randomY + 175;
    leftArrow = [SKSpriteNode spriteNodeWithImageNamed:@"arrow"];

    leftArrow.size = CGSizeMake(leftArrow.size.width/1.2, self.frame.size.height/22);
    leftArrow.position = CGPointMake(CGRectGetMidX(self.frame) - 230, yPoint);
    leftArrow.zPosition = 50;
    leftArrow.alpha = 1;

    SKAction* action1 = [SKAction moveToX:leftArrow.position.x + 30 duration:0.5];
    SKAction* wait = [SKAction waitForDuration:0.75];
    SKAction* action2 = [SKAction moveToX:leftArrow.position.x + 470 duration:1.5];
    SKAction* sequence = [SKAction sequence:@[action1,wait,action2,destroy]];

    [self addChild:leftArrow];
    if (deadDown == 1 || deadUp == 1 || didIntersect == true)
    {
        [leftArrow runAction:destroy];
    }
    else
    {
        [leftArrow runAction:sequence completion:^{
            if (ii != 1)
            {
                if (didIntersect != true)
                {
                    score++;
                    if (score == 100)
                    {
                        backgroundScore.fontSize = 300;
                        backgroundScore.position = CGPointMake(backgroundScore.position.x, backgroundScore.position.y + 30);
                }
                strFromInt = [NSString stringWithFormat:@"%d",score];
                backgroundScore.text = strFromInt;
                }
            }
        }];
    }
}

I am also using this in my didmovetoview function

self.scaleMode = SKSceneScaleModeAspectFill;