https://postimages.org put your image onto it with no expiration and no resizing then copy the link after "Direct link:" and put it on your "Avatar URL" or "Banner URL" in Neospring's edit profile settings, scroll down to the bottom and click "SAVE CHANGES"

THAT'S LITERALLY HOW YOU DO IT MAN you have to be doing it wrong in some way

Make sure you put it on Avatar URL and not Anonymous Avatar URL or anything else