Can't login to backend

Hi there, please help me. I cannot login to the backend of my website anymore.

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I had a memory issue with the ISP sorted out but they wrote the following:

Upon browsing to modelsnmaps.co.za/wp-admin, the following error message is present on the site: 

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 20480 bytes) in /usr/www/users/modelwmzdj/wp-includes/class-wp-query.php on line 593

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 32768 bytes) in /usr/www/users/modelwmzdj/wp-content/plugins/woocommerce/packages/action-scheduler/classes/abstracts/ActionScheduler_Lock.php on line 1

It appears as though the files class-wp-query.php, as well as ActionScheduler_Lock.php, are causing the site to run out of available memory. You may consider disabling the woocommerce plugin by renaming this folder by making use of file manager [Links visible only for registered users], in order to determine if this allows you to sign into the backend of your website. 

I would suggest looking into the above-mentioned files to determine why these scripts need more than 256MB of memory in order to load, as it is very uncommon that a script needs this amount of memory in order to function. 

Please help. Thank you!

Regards Alex