loading images, css and fonts from site url

I changed the site url to example.com/blog but the wordress url is blog.example.com, still css, images and fonts are loading from blog.example.com, is there any way to force wordpress to load files from site url?

P.S: example.com/blog is loading blog.example.com through nginx proxy, so I don't want to use .htaccess rewrite url for this purpose. (because it make a redirect loop)