Lost ssh contact while changing parameters

First I created a pair of public/private keys on my access pc
I struggled copying it so I added it to my umbrel manually at ~/.ssh/authorized_keys
/etc/ssh/sshd_config and I turned PasswordAuthentification to no
service sshd restart
Closed my session, clueless
Now the desktop client of course wont connect anymore
Im trying to log through my console with the command:
ssh umbrel@umbrel.local
and I get:
umbrel@umbrel.local: Permission denied (publickey).

Now I dont have a clue how Im supposed connect through ssh and I feel very bad about myself.
If anyone can help, it would be greatly appreciated.

Would reflashing the sd card be an easy way to solve my problem?