Unhappy [Q] Please help!

I have samsung galaxy core gt-I8262.I Installed philZ cwm recovery which was successful.After that I tried to install custom rom(SaMyKAT) which was also successful but now when I reboot my phone,It gets stuck on the "samsung galaxy core logo"and also when the "samsung" logo appears,It shows a yellow triangle at the bottom with an exclamation mark inside it.What to do now,I don't want to flash stock firmware again with odin,Any other method apart from that???Please help me!!!!!!!!1: crying: