I'm scared of losing everything I currently have if I run an upgrade, what's the best way going about it?
Just make sure you have a backup. Did you make all your changes to a sub-theme? If so, you have nothing at all to fear. If you made your changes directly to UI.X (which you should never do), you might be in a bit of trouble but that would be any theme not just UI.X.
Also thank you for the update Audentio, your designs are impeccable. Would expect something like this as a custom, not a $30 resource skin!
I appreciate your kind words very much!