When I removed my account and tried to add it back on it says it already an account that...

Hi there

please try the manual power cycle steps like mentioned on the following link, be sure to wait at least 60 seconds before powering on again:

http://support.xbox.com/xbox-one/console/power-cycle-console

After that check the profiles on the console, if yours (one with the same email address) is not showing try redownloading it.

Let us know the results

If no one of the previous solution works, try a factory reset https://support.xbox.com/en-US/xbox-one/console/reset-console-to-factory-defaults

Are there any other accounts on the console?

If so sign into those accounts and go to settings and under the account tab go to sign in security and passkey and it will show you what email is associated with that account you are signed into and make sure that the email you are trying to add to the account
is not attached to any of those other accounts.

If you find that it is and you do not remember the email for a particular gamertag but know the gamertag you can contact xbox support by going to support.xbox.com/contact-us and give them the gamertag and they can look up the account attached to that gamertag
and if they can verify ownership of the account they can give you the email address associated with that account.

I removed my account from my consol and now i am trying to add it again, but when i have typed in my e mail and password it says the account has already been added. But the account is not there. Plz help

Have you tried restarting your console and adding the account again if it is not there?

I think your right but for some reason can someone help me with this problem? When I made this new account on my Xbox I tried to play skyrim with it and when I went to the the add-on screen it said "no add-ons downloaded but in this account I am using I
already bought the dawnguard and when I try to bit it on this account it says already downloaded (which it is but won't work on my other account) and free but when on the other account it says I have to bit it again can someone help me.