Help fixing my Opencart site

Hello A week or so ago my page stopped working. I would really appreciate any insight or help as to how to fix it. I will try to include as many details as possible. Here we go. 1. I went to my site and noticed the header had an error code in it and some of the shopping cart features seemed a bit buggy as well. Here is the error that was showing in the header Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/uvapeca/public_html/system/database/[login to view URL] on line 6 Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/uvapeca/public_html/system/database/[login to view URL]) in /home/uvapeca/public_html/system/library/[login to view URL] on line 11Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/uvapeca/public_html/system/database/[login to view URL]) in /home/uvapeca/public_html/system/library/[login to view URL] on line 11Warning: Cannot modify header information - headers already sent by (output started at /home/uvapeca/public_html/system/database/[login to view URL]) in /home/uvapeca/public_html/[login to view URL] on line 179Warning: Cannot modify header information - headers already sent by (output started at /home/uvapeca/public_html/system/database/[login to view URL]) in /home/uvapeca/public_html/system/library/[login to view URL] on line 45Warning: Cannot modify header information - headers already sent by (output started at /home/uvapeca/public_html/system/database/[login to view URL]) in /home/uvapeca/public_html/catalog/controller/journal2/[login to view URL] on line 28 - See more at: [login to view URL] ... [login to view URL] 2. They sent me here for help [login to view URL] -- I then tried playing around with the [login to view URL] and keep getting different errors now. 3. Seems there is something with the code at the end it does not like. Here is the error that is currently being display on my webpage [login to view URL] Parse error: syntax error, unexpected end of file in /home/uvapeca/public_html/system/database/[login to view URL] on line 75 4. The CRA are looking for me to file my taxes and I cant get to my reports in my admin panel either because of this error. I would seriously appreciate any help I could get on this. I have tried to fix the error by myself and I fear I am making it worse. 5. Here is what my current [login to view URL] file reads. <?php if (!class_exists('MySQLi')) { final class MySQLi{ private $mysqli; public function __construct($hostname, $username, $password, $database) { $this->mysqli = new mysqli($hostname, $username, $password, $database); if ($this->mysqli->connect_error) { trigger_error('Error: Could not make a database link (' . $this->mysqli->connect_errno . ') ' . $this->mysqli->connect_error); } $this->mysqli->query("SET NAMES 'utf8'"); $this->mysqli->query("SET CHARACTER SET utf8"); $this->mysqli->query("SET CHARACTER_SET_CONNECTION=utf8"); $this->mysqli->query("SET SQL_MODE = ''"); } public function query($sql) { $result = $this->mysqli->query($sql); if ($this->mysqli->errno) { //$mysqli->errno if (is_resource($resource)) { $i = 0; $data = array(); while ($row = $result->fetch_object()) { $data[$i] = $row; $i++; } $result->close(); $query = new stdClass(); $query->row = isset($data[0]) ? $data[0] : array(); $query->rows = $data; $query->num_rows = $result->num_rows; unset($data); return $query; } else { return true; } } { trigger_error('Error: ' . mysql_error($this->link) . '<br />Error No: ' . mysql_errno($this->link) . '<br />' . $sql); exit(); } } public function escape($value) { return $this->mysqli->real_escape_string($value); } public function countAffected() { return $this->mysqli->affected_rows; } public function getLastId() { return $this->mysqli->insert_id; } public function __destruct() { $this->mysqli->close(); } } ?>