delete option error - hacked - please help

Hello, recently my e-mail account has been hacked. I received an e-mail saying , "Thank you for registering a TeamViewer account. To activate your account, click the link below." (in Chinese), although I didn't set up an account. Today I decided to check it, I tried to reset the password by entering my email address, then I got a message with a password reset link. After redirecting me to TeamViewer, I was shown that the account has not been activated yet. I activated the account and an unknown device appeared in the list of computers and contacts. The device is offline. I was able to remove this device from the list of trusted devices, but I cannot delete the group in which this device is located. After entering the "edit groups" option and clicking "delete" in the left bottom corner, I get an error window message: "The group you want to delete has computers assigned. Before deleting a group, remove all computers from it." I'm afraid someone has access to my laptop. I want to delete the account, but I'm afraid that's not enough and someone will still have access to my laptop. I wanted to remove this device/group first just to be sure but I don't know how to do it. Is account deletion enough? Please help.