I used Google Drive for image hosting until they disabled 3rd party with the redesigned Drive.
You could start a private blog there, and use that for hosting. Be aware that many of the links no longer end in jog or png but gibberish.
Dropbox is still out there, but you must use a workaround for images to render.
For both Postimage and Imgur, make you you register an account and upload that way to ensure longevity.
I have thousands of images for reviews and stories, and have had to reupload to various sites several times over the years. Hope your stash is not too massive.
ALWAYS back up your images in the cloud. That is a given, but many forget or forego.
Good luck out there.