rooted phone having problems with switching on

I recently rooted my samsung galaxy s5, i did some shit on one of custom roms, i thought I was installing the new system or something, it got me into the boot system, i chose apply (something) and it restarted... ever since I cannot switch my phone. I mean it does switch on but then the home screen is completely black, and the notification shows ''unfortunately, settings has stopped'' it shows a notification to almost every single app saying it stop working. Once I press ok every single notification, it just black screen, nothing changes if I press anything. I tried to restarting, rebooting, re-rooting...nothing. Any ideas ?