OP, you need to get help with your mental health.
You keep making these posts showing clear signs of paranoia and delusions.
Like, how are either you able to looks up your "the only name on record" claims in the first place, just search social media profiles? Is that how you found this guy?
Now you're stalking some online person because of a fluke coincidence?
Like, just a few days ago you had a post saying all these other people were stealing his identity, now it's online strangers?
Asking if you should reporting him missing after years?
It's just at the point people just need to tell you bluntly:
Seek mental health help before things get so bad you instinctively reject anything that goes against delusions.
I know it sucks to hear, and you're going to think it's part of a conspiracy, but you need to get professional help.