Xorg not working with bumblebee (no nouveau, intel as main GPU)

I've been trying to get Xorg to work the whole day to no avail.
I've tried like 15 different methods to make it work to no avail.

System:
Dell XPS 15Z
8GBs DDR3 1333Mhz RAM
NVIDIA GT 525M
Intel i5-2410M

I have the NVIDIA drivers from ELRepo installed (Ver. 384.111-1.el7 - As per recommendation of nvidia-detect).
What I think is the problem is the following:

(EE) [drm] Failed to open DRM device for (null): -22
(EE) modeset(0): eglGetDisplay() failed
(EE) modeset(0): glamor initialization failed
(EE) modeset(G0): eglGetDisplay() failed
(EE) modeset(G0): glamor initialization failed
(EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)

but haven't found a way to fix it, every "solutions" yields to a dead-end, I deleted the xorg.conf (as some suggested in other forums) but nothing changed.

I have attached the full log, xorg.conf.nvidia (from /etc/bumblebee/xorg.conf.nvidia) and bumblebee.conf (both .conf files were uploaded as .txts because it won't let me upload .confs) in case there's something else that I didn't find.