It seems like you had a bad luck with guessing new user names.
I checked your profiles history.
EE2 uses "nicknames" and "unique nicknames". It seems like you created an account with nickname "Lego***", which was created earlier by a different user. Then it asked you to change the nickname, and it set the new nickname as "unique", but you were still supposed to log in using the "Lego***" nickname. The new/different nickname would be visible after logging in.
Then you renamed your account again using the ee2.eu/multiplayer/accounts website, and set it as "ofer". Then you created another profile using the "Create Account" button, and you named it "ofer", which was again already in use, because of your rename on the website. It asked you to set the "unique nickname", and you set "ofer293". After that you shouldn't have changed the nickname on the logging-in screen. You should have used "ofer" and it would log you in as "ofer293". However, you again clicked to create a new account, and entered "ofer293". Once again it created another profile, but you didn't set the unique nickname for it (probably got confused and cancelled). And finally you made an account with something new and not used before - "oferk", and it finally let you log in
I think this is a case 1 on million, very bad luck with nicknames and actions made
If not that account change on the website it would probably work for you at the second attempt.
If you can, please verify if it works.
1. Enter the same mail you used for all accounts.
2. Enter the password, then try to log in using the following nicknames:
If possible, please let me know if it worked.
*** - I hidden the "original" "Lego" nickname as I'm not sure if it doesn't contain private details (name), but you should remember what it was.