Howdy @Felisa18,
I definitely understand wanting to have your own separate login, especially if you mainly take care of the bills each month. I would be happy to provide available options for you. 
Currently there is not a way to have a completely separate main login for one account. However the good news is you can add yourself as an authorized user, which would allow you to access your account with your own separate login.
In order to add an authorized user, please follow the steps below:
- Go to Profile> Account users.
- If you have more than one account, select the wireless account from the dropdown at the top.
- In the Authorized users section, select Manage authorized users.
- Select Add an authorized user.
- Complete the fields to receive a validation code.
If you’re interested in what kind of permissions an authorized user may have, we do have a user permission chart which will go over all the tasks they are able to perform for a wireless account.
I hope you find this information beneficial! If you have any further questions or concerns, please feel free to reach out to us. We’re always more than happy to help! Have a splendid rest of your week.
Austin, AT&T Community Specialist