Error to many requests

try:

– deactivating ALL plugins temporarily to see if this resolves the problem. If this works, re-activate them individually (one-by-one) to find the problematic plugin(s). When you can’t get into your admin dashboard, try deactivating via FTP or SFTP or whatever file management application your host provides (also read https://codex.www.ads-software.com/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F). Also remember to deactivate any plugins in the mu-plugins folder. The easiest way is to rename that folder to mu-plugins-old.
– If that does not resolve the issue, try switching to the unedited WordPress default Theme for a moment to rule out any theme-specific issue. When you don’t have access to your admin area, you can switch to the default theme by renaming your current theme’s folder in wp-content/themes and adding “-old” to the end of the folder name using via FTP or SFTP or whatever file management application your host provides. Alternately, you can remove other themes except the default theme. That will force your site to use it.

most of the times when you open lots of pages from your blog it happens, but if you closed all the tabs and still you have the problem try to deactivate all of your plugins, go to file manager in your hosting account then rename your plugins folder to plugins-old, then log into your wordpress and search for plugins affecting your site