So I wanted to edit my account like avatar icon and stuff, and when I did in Mathematics, It said "Sorry, but this E-Mail is already registered. If it is yours, please log in above. If you believe this is an issue, then request an Account Recovery". So the weird thing is that I was logged in already, because the only way I got to the edit profile screen was because I clicked on my profile icon in the top banner. It also was recognizing that it was my profile because it allowed me to attempt to edit it. Also, There was nothing related to logging in above the message that said I can log in above. So I checked below the message too, and I found nothing. I clicked the link to recover my account and it didn't do anything. I tried twice. So then I opened it in google and the same thing happened. The only site that says "Successfully edited Profile" is in Stack Overflow, but that is the only site that does not update my badges (See my other question on "Some sites showing badges achieved but not others"), So I am wondering what is going on.
Turns out it was the same issue as the one described here, I had a second separate account and the system was confusing that for this one.
As the developer said there:
If anyone else is reading this and has the same problem, please contact us and we will fix it for you.
I have contacted SE team via the contact form and they merged the accounts.