You're not killing the desktop when you switch like that. The desktop is still there, and you can get back to it with <ctrl> <alt> <F7>
It may be <ctrl> <alt> <F5>, but it's probably <F7>
ANd you don't have to do all that to use bash
In Gnome, go to the applications menu, and I think it's the "system tools" submenu that has the "Terminal" or "Gnome-terminal" option. Anyway, it's somewhere in the menu. It'll create a new window, and run bash from there. There's no need to switch back and forth.