I decided to delete my old login email from my Stack Exchange account, hoping that the system would then only recognize my new email for login.
However, my associated account profiles and reputation are gone (except TeX where my reputation is set to 1). When I login on Stack Overflow however, I can still see my reputation on the other subsites.
(removed, can only post two links with this low reputation)
How can I finally make that email change without losing all the reputation associated with my old email address?
As I see now, I am also only a user+random number, not my usual nickname anymore, while my usual account still exists (https://stackoverflow.com/users/1829329/zelphir) and should be associated with this post.
Also I still see my old email address in my Stack Exchange account, although that was the one I deleted.
Instead, now the two other email logins, which were in there before I deleted the old login disappeared! Exactly the opposite of what I wanted.
Update
When trying to fill the form for merging accounts on the contact page, I get the following issue:
oops! this isn't a link to a valid profile
for both accounts.