I'm not clear exactly what you clicked on to block the images. If it was the little Show Images box in the Edit Options section of your CP, go there and re-click it. Then you should be able to see images again when you view the site. That's how it works for me, anyway. I think the "show images" control only changes what
you can see on the site. It doesn't change anything for anyone else's view of the images you've posted. You're the only one who won't be able to see it. Everyone else still can, unless they, too, have set their options not to display images.
If you did something to the settings of your
computer in an effort to block images, I'm afraid I wouldn't know how to help you undo it.
If there's a pic in your gallery that you don't want anyone else to see, you can remove it. Just click on the image you want to remove, then click on Image Tools over in the right hand corner of your gallery. Select the first item, "Edit," on the drop-down menu. The page that comes up should have a little box to click that says Delete.
If the pic you don't want anyone to see is in your journal, you'll have to go to your User CP, select Edit Options, then Show Images. Then go to your journal and find the image you want to remove, click on Edit, then highlight and delete the code for the image. If that's the only text in the box, you'll have to enter something else. Lot's of people just use "Nevermind" or something similar.
Or am I not understanding what it is you want to do?