Hej Mr. Phillips. Thank you so much for the response.
I know the password to the account, so that is not the issue. I get the spinning wheel when I try to log in, and don't get anywhere. This is after a sudden error when I filled my HD with to much data a couple of days ago.
After installing an OS on a separate HD I could go in to my main HD and erase some files, now I have anough storage so that my mac can run properly. The only thing is that I tried to creat a new user from "single user mode" (cmd + s) with the ... .AppleSetupDone command. This didn't work, so backtracked and now I can't find my original account, but I have managed to creat new ones. Though I can't enter any of them, I just get the spinning wheel.
So now I'm thinking I should reinstall my OS. But I'm afraid of loosing everything.
Thanks