All Plugins Disappeared After WordPress 4.9 Update

This is the message I received from my webhost.

Yes, it appears one of your plugins is overwriting the /wp-admin/index.php. I have replaced it and made a copy in there /wp-admin/indexGOOD.php as soon as you view the plugins it gets overwritten. You will need to figure out what plugin is breaking this.
If you want me to continue it will be a paid charge of $50 per hour. Let me know if you want me to fix this issue for you.

When I initially attempted to access my page via WordPress admin, these are the error messages I received:

Warning: require(/home/angelicy/public_html/wp-admin/wp-blog-header.php): failed to open stream: No such file or directory in /home/angelict/public_html/wp-admin/index.php on line 17

Warning: require(/home/angelicy/public_html/wp-admin/wp-blog-header.php): failed to open stream: No such file or directory in /home/angelict/public_html/wp-admin/index.php on line 17

Fatal error: require(): Failed opening required ‘/home/angelict/public_html/wp-admin//wp-blog-header.php’ (include_path=’.:/opt/cpanel/ea-php56/root/I’d rather/share/Pear’) in /home/angelict/public_html/wp-admin/index.php on line 17

Now when I try to update via WordPress admin, I get:

https://www.AngelicTouchHealthandWellness.net is currently unable to handle this request. HTTP ERROR 500

Any help appreciated.

Namasté
Debra

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