Gallery images blurry on retina display

I recently bought a new computer, retina display, and now all my images look blurry in the large gallery view. The images look fine on the blog when I just upload them straight into the posts. They are all at least 1000 pixels wide and 72 dpi or higher. I’ve tried creating the images at 1700 pixels wide and 200 dpi and uploading them into the gallery but they are still all blurry. I’ve tried rebuilding the thumbnails also but they still look blurry. No idea what is going on PLEASE HELP! I’m an artist and potential clients view my online portfolio all the time when deciding to hire me, I can’t have images that look fuzzy on my site.
the URL is https://www.rebeccaevans.net

Thanks,
Rebecca