Sizing Problem

I’m new to WordPress and I’m putting together a website (www.hanauhealthgroup.com). I resized my pix and the site looked good. Then I got a message saying a theme upgrade was available, so I upgraded. Dumb mistake. Now the small images (heights in the mid-450 pixel range) are bigger than the screen on my 2160 x 1440 display. I have the same problem on other machines and using other browsers.

Any help on how to fix this problem much appreciated!

Thanks,

Brian