I have the problem that my minecraft was revoked.
So i buyed a new one.
But my problem now is that i cant use my old Username.
It says all the time that the username or password is invalid.
But i use the right username and the right password.
I want my old username ._.
if i cant use it, i lose all my things on my server ._.
you could try contacting customer support https://help.mojang.com/customer/portal/emails/new and explain what happened with your old account and that you bought a new account, they may (or may not) be able to free the old name up and apply it to your new account (not sure if they can, but worth asking)
You could also try to contact the admins of your server and explain your problem. There is a way of transferring the content from your old account to the new one, but it's doubtful if they'll take the time to do so. But they might do, so try it, you can't loose anything.