I can't even get into wp-admin due to issues.

Everything is a broken mess and I can't even get into wp-admin due to issues.

So, I recently upgraded my website to VPS hosting earlier this week. Was supposed to take a few days and since it took longer, I contacted support today. Figured out it seems to be a memory/plug-in issue with Wordpress (the main website is built with a wordpress back-end due to it being a blog-related site), but we've hit a stopping point and I was told to look into Wordpress fixes

This is what the WP-Admin page just shows:
Notice: The called constructor method for WP_Widget in PlumwdTwitchStatusWidget is deprecated since version 4.3.0! Use
__construct()
instead. in /home/cryst153/public_html/wp-includes/functions.php on line 3892

Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 12288 bytes) in /home/cryst153/public_html/wp-admin/includes/class-wp-screen.php on line 1160

Fatal error: Class 'WP_Screen' not found in /home/cryst153/public_html/wp-admin/includes/screen.php on line 232

This is the debug log since I... set that up so it stopped showing on the pages: crystal-dreams.us/wp-content/debug.log