Wait, what? You mean a subreddit? And someone else claimed that subreddit was haunted by a djinn that that kind of random power… and you believed him, why? 
That make zero sense and it’s not how any of this works.
Because you believed him you let him curse you with fear, and you manifested your fear. This is the same way lazy mages curse people - they just tell hem they were cursed and the people believe it and blame every bit of sickness and back luck on that. It’s a scam we have talked about before on here.
That’s not how djinn attachments work. Spirits can’t even see the bits and bytes they see people, and they can come though the people you interact with when they know you exist, but you won’t get cooties off subreddits without people being the carriers.
Stop listening to trolls and protect your energy MUCH better - get up your shields and wards properly and trust them, not randoms online.
I suggest you do not do any more subliminals or online forum stuff until you have fixed your spiritual hygiene, it’s not going to take long and it’s worth the peace of mind.
If you can get the first book in this topic, that will set you up for life with great protections Unofficial Tutorials: Spiritual Hygiene & Defense Basics Collection
No - only you can allow this and make it happen. So don’t do that to yourself.