Anthony, thanks for the help! I found my mistake. I grabbed the wrong PHP function for exp. It was just the same as java (exp). I also put it in backwards, ouch... long day!
For those who need it, the PHP function for converting web mercator to latitude longitude is:
function convert($mercatorX_lon,$mercatorY_lat) {
$x = $mercatorX_lon;
$y = $mercatorY_lat;
$num3 = $x / 6378137.0;
$num4 = $num3 * 57.295779513082323;
$ex = ($num4 + 180.0) / 360.0;
$num5 = floor($ex); // Math.Floor((num4 + 180.0) / 360.0);
//echo $num5 .'and'.$ex; die;
$num6 = $num4 - ($num5 * 360.0);
$num7 = 1.5707963267948966 - (2.0 * atan(exp ((-1.0 * $y) / 6378137.0)));
//echo $num6 . ' and ' .$num7; die;
$mercatorX_lon = $num6;
$mercatorY_lat = $num7 * 57.295779513082323;
return $mercatorX_lon.','.$mercatorY_lat;
}