Google have gone to some lengths to prevent hotlinking photos basically. Chances are if you get a link working it won’t work after a while.
I use imgur now for random crap photos if it’s not something already on the net I can link to. Or if it’s anything of mine that’s an ok photo it will be in Flickr and they have a handy share button complete with BB code.
imgur is a bit fiddly to get to the links. If you’re on the image page, take the link and add the extension to it. Or if it’s your photo, go to your profile -> images, click on image and it will give you buttons to copy including BB code.
Another option is sharing links from OneDrive, which is where I have the master of all my photos, but not sure on doing that as I tend to move things about.