Try to use codeigniter in correct way.
SUGGESTION: Since it is a library you don't have to include it precisely. Move the library file to applications/libraries
directory and -
1) You can autoload it in config/autoload.php
$autoload['libraries'] = array('my_library');
2) Or you can specifically load into your required controller
<?php
class Something extends MY_Controller
{
public function __construct()
{
parent::__construct();
$this->load->library('my_library');
}
public function my_function()
{
...
}
}