I was adding a new post to my site (http://studio279.co.uk) which uses the structure theme. I was adding the featured image so it would display correctly on the home page. After uploading the image from my computer the image did not appear. I tried again three times until it finally showed the picture, both in the media gallery and the "Set Featured Image" section of the new post interface. However, after publishing the post my site has been very slow, and has not been loading some of the images on the homepage. I tried the site again later, and was met with an error message HTTP 500 and the site did not display. While the site now seems to be back online, it is again slow to load images. Is there a reason for this, e.g. something to do with the amount of pictures in the media gallery, or some other reason? And is there anything I can do to correct it, or will it right itself soon?
The blog I need help with is studio279.co.uk.