You’ve installed home-manager separately from the system, so rolling back your system generation will not change your home-manager configuration. If you want that to work, share your config afterwards and we can help you set it up correctly.
Your home-manager config is clearly broken. Presumably you configured your window manager with it, and because your home-manager config doesn’t set it up correctly, you immediately crash and end back up on your login screen.
Can you switch to a tty and log in from there? You can bring one up by pressing Ctrl+Alt+F3