Load of errors appeared on top of my page and no images load after change from mysql to mmsqli

Hi Guys, long story short i have been having an error about mysql being deprecated that seems quite common. I changed the config files to point to mmysqli after following some guides, however now i get a load of new errors and reverting to a backup does not restore the function of the site, i cannot login to admin panel at all either.

[code]Notice: unserialize(): Error at offset 0 of 5 bytes in /home/mletools/public_html/index.php on line 65

Notice: unserialize(): Error at offset 0 of 5 bytes in /home/mletools/public_html/index.php on line 65

Notice: unserialize(): Error at offset 0 of 73 bytes in /home/mletools/public_html/index.php on line 65

Notice: unserialize(): Error at offset 0 of 5 bytes in /home/mletools/public_html/index.php on line 65
Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/mletools/public_html/index.php:65) in /home/mletools/public_html/system/library/session.php on line 11Warning: Cannot modify header information - headers already sent by (output started at /home/mletools/public_html/index.php:65) in /home/mletools/public_html/index.php on line 177Warning: Cannot modify header information - headers already sent by (output started at /home/mletools/public_html/index.php:65) in /home/mletools/public_html/system/library/currency.php on line 45[/code]

Website is www.mletools.com

Ive been googling for some time to no avail, i have reasonable tech knowledge but dont really know PHP at all. Please help!

You should have changed to MySqli , NOT MMSqli, to make it work again,
and if you still have no mysqli.php File in your System, you may download
one here:
https://www.opencart.com/index.php?rout ... rch=mysqli

Good Luck !
Ernie