No one other than VSTF, Helpers and FANDOM can change your profile picture. If the picture is too large, then it cannot be added. If that is your issue, try compressing the image or rescaling it to make the file size smaller. If it is not the issue, then either try again later or contact FANDOM about it.
New users cannot upload (inlcuding profile pics) images on this wiki. You can either go to a different wiki and upload it from there (like the CC wiki) or you wait for the allotted time given for new users to pass.