Please help urgenttttt

Hi guys,
I have one WP blog which I run since 6 months. All were going everything fine but today I noticed that the images of the posts have automatically became larger in size and the entire site became a mess because of big images. On discussing it with my friend, he told me that newer version of wordpress automatically increases the image site. Yes I updated to latest version.
Now it is not possible to manually go to each posts as the posts are in thousands. Is there any ways i could use…
Please help urgenttttt

See original post by softech02