Default Stuck at bootlogo

Hi, last week my phone started behaving very weird, out of nothing the phone freeze and stopped working and reboots itself and then got stuck on the boot logo, I tried to go to recovery via bootloader, but it didn't work, I tried everythging but it the only thing useful was connecting it to the pc and wiping cache via fastboot. This happened like 3 times a day. Now I have reflashed the stock firmware, installed some apps, xposed and other things, and when my device was ready, started behaving the same way like before, I don't know what to do now. please help.

Im using retail us 4.4.3 firmare.
this never happened with 4.4.2, is there any way to downgrade?

I followed this guide to restore stock firm: http://forum.xda-developers.com/show....php?t=2542219