Default [Q] customising left screen blank......

Hi.... have a note 3 copy.. running 4.2.1.. i rooted it and added a few programs to play around with it and change start up video etc... i chose a random custom rom and installed it... all was well... made another change along those lines using rom toolbox, had a warning pop up saying that device may not be compatable with this change... and i then backed up my phone before progressing... or so i thought.. when i rebooted... a blank screen greeted me and thats all i get... is there any way to undo that last change... the backup didnt take place... if i could see what i was doing i could get back in there and undo it... but alas i can't....