Help!! Can't get my pictures to upload! Anyone have any ideas??

Hello...... If anyone could help me with my blog right now, I would be so grateful!!! I am having trouble uploading pictures to my blog (and even my Etsy store, too!!) Can't figure out what is going on! What's happening is whenever I go to post something and click on the icon for Add Image, it does bring up the window to find the picture, so I've done that and then clicked on the image I want to upload but then the window is stuck, nothing happens!! I noticed in that window, it had gone to "large image" instead of medium, which is what I ususally use (medium). I clicked medium again and it keeps going back to large. It never did that before. I also reduced the # of posts I have on each page to 5 posts. I did have it set at 7 days posted on one page, but I thought that was too much. Changing that didn't seem to do anything!! I am desperate!! I can't post anything on my Etsy store either!! Does anyone have any idea what I am doing wrong or if there's something wrong with my computer?? I tried hitting refresh, that didn't seem to do anything. I never had any trouble uploading pictures before!! I also changed the setting in the browse window to "all pictures" instead of "all files". That didn't work either. Please contact me if you could help me at all. I really need to post some things on my blog andmy Etsy store but just can't figure out what's wrong!! Thank you so much!! Debbie