'Set Warranty Bit: Recovery' Samsung doesn't boot

I have a Samsung Galaxy J5 and it isn't booting since I patched an app with Lucky Patcher (first time I tried it). I have had the root for some time, with no problems, but now I boot it and it goes black after showing the logo and 'Set Warranty Bit: recovery' for a second. I have a backup with Titanium Backup in my PC, and would like to know if I should **flash a custom ROM** I found for my device or **flash a stock version** (custom ROM works for everyone and comes with instructions, but I don't trust so much the stock version). Also, the custom ROM has a lot of steps, but there is no cyanogenmod version for the J5. Thanks in advance! (also, is there any other solution?)