Unable to uninstall the plugin

Hey guys, I have the following problem. I got a WordPress website to “fix” it and “speed it up”. I installed WP Optimize to try and clean the database a little because it’s 350MB. Sadly I wasn’t able to do it as most of the database size is coming from the _postmeta table. Anyway, since the plugin is no good for the current situation, I tried to unistall it, but I can’t. I’ve used this plugin before on multiple wordpress sites to optimize the database and so far I haven’t got any problems with it, until now. This is the error I’m getting when I try to uninstall it:
“Uninstall failed: .wp-die-message { display: none; } Fatal error: Uncaught Error: Call to undefined function wp_optimize_minify_config()in /home/***/***/wp-content/plugins/wp-optimize/minify/class-wp-optimize-minify.php on line 128Call stack:WP_Optimize_Minify::plugin_uninstall()wp-content/plugins/wp-optimize/wp-optimize.php:2181wpo_uninstall_actions()wp-includes/class-wp-hook.php:287WP_Hook::apply_filters()wp-includes/class-wp-hook.php:311WP_Hook::do_action()wp-includes/plugin.php:478do_action()wp-admin/includes/plugin.php:1246uninstall_plugin()wp-admin/includes/plugin.php:956delete_plugins()wp-admin/includes/ajax-actions.php:4545wp_ajax_delete_plugin()wp-includes/class-wp-hook.php:287WP_Hook::apply_filters()wp-includes/class-wp-hook.php:311WP_Hook::do_action()wp-includes/plugin.php:478do_action()wp-admin/admin-ajax.php:175Query MonitorThere is a critical error in your WordPress.”
I also have Query Monitor installed and I don’t really understand why it is showing also in the error message. I tried to deactivate Query Monitor and to uninstall WP Optimize in order to check if the error is coming from a conflict between them, but the result is the same. Tried even uninstalling Query Monitor and then uninstalling WP Optimize – again same error.. Tried to deactivate all other plugins and then uninstalling – same thing.. Any other ideas what to do? Thanks! ??