Started again with site’s backup.
I disabled Woocommerce. Updated it. Then I smashed all images. After that I enabled Woocommerce.
Site’s speed is normal again and everything works.
I disabled all plugins.
I disabled Woocommerce. Then I updated it. It was success!!!
So I turned it on. I had speed problems. I managed to figure out, that Woocommerce was making my site slow (turning plugins on one-by-bone). Then I found this article. https://woocommerce.com/posts/woocommerce-site-slow-fixes/
I disabled Woocommerce. Then smushed images smaller. And after enabling Woocommerce again, the speed was again normal.
So problem solved.
