memory issues which i cant seem to fix

I have problems across multiple of my websites, and from some error reports I believe it’s due to insuficient memory for php, but I can’t seem to fix the issue.

I tried fixing php.ini and wp-config with memory increase, but to no avail.

Some of my sites such as and show the whote screen of death one moment, and a bit later show up correct again, after which it goes back to the previous state.

My site has an error report on the very bottom of the page. The slider function doesn’t work at the moment.

A back up from 3 days ago doesn’t have these issues.

The dashboard of my site disappears when I try to load a plugin that works fine on my other similar sites. And then also shows the same memory issues.

I have no clue how to fix this and any help is very much appreciated.