i keep feeling paranoid that maybe somehow someone must have complained against me and got me blocked from all the major firms and there is a huge data base that companies look at before hiring you. I have also trolled on some websites like reddit etc and have mostly thought it to be harmless fun but what if the firms have a list of all the posts that i have made in the past. I also used to visit a form called economics job market rumors, which has been mentioned in the nyt etc and have trolled the forums and have also put forward my political views. There have been many friends of mine who have fought with me and have told me that they will anonymously send mails to firms to block me.
I have also interned at a bulge bracket investment bank a year ago and didnt perform too well due to some issues. Are my fears grounded in reality? Is my career ruined and will i be blocked from all the major countries for putting forward my political opinions? i have deleted all my social media a few months ago and am only on whatsapp

do firms have a database in which they can track my ip address or any other address and get me blocked from everything? I am currently working in a startup but no firm is responding to me. My friend also told me that EJMR and reddit is filled with influential academics who can get me blocked

PLEASE HELP ME AND TELL ME WHAT I CAN DO AND IF MY CAREER IS RUINED

You are worrying unnecessarily. Ignore these chattering paranoics. Focus on improving yourself, and the visibility your value. Maybe look for a free evaluation of the CV and LinkedIn.

There is not a huge secret database. Anonymous email are ignored. Of course, firms do not allow them to decide their hiring. Yes, firms will search social media to assess you. You can simply search for yourself to see what they will find. If it discredits you, remove it.

You are worrying unnecessarily. Ignore these chattering paranoics. Focus on improving yourself, and the visibility your value. Maybe look for a free evaluation of the CV and LinkedIn.

There is not a huge secret database. Anonymous email are ignored. Of course, firms do not allow them to decide their hiring. Yes, firms will search social media to assess you. You can simply search for yourself to see what they will find. If it discredits you, remove it.

No one, specially companies, has the time nor the resource to maintain a database - secret or otherwise - with a list of names, let alone email/ip address etc.

Firms have a hard time keeping track of their customer database, financials, costs, customer billing etc as-is. They don't have time to go out of the way to get you - specially when it's a drain on their resources and revenue.

As a general rule -not talking about you specifically but generally speaking- it is never "everybody else's fault" but the fault of the individual

Try to make yourself more attractive with certifications, degrees (MBA?), better CV etc.
Maybe you are targeting wrong jobs or wrong countries

Good advice. Also, I'd add that there is a huge amount of value in targeting networking. Getting your name and face out there, in front of the right people, is very important.