Default [Q] Nexus 7 2013 LTE reroot doesn't work, tried everything.

Backstory:
So, I have a 32GB LTE Nexus 7 that I rooted as fast as I got it under 4.3 and flashed custom recovery because I thought I would go CM like I always do.
But I actually didn't need anything else than root and CM tends to have a sucky cellular connection. So I used it and used it and was happy.
But there was a 4.3.x update that I installed that obviously broke root and OTA rootkeeper didn't help. I tried to reroot it (because I'm lazy) with wugfresh's rootkit.
It didn't work, just like it didn't manually over ADB, so I gave up and tried again when the KitKat OTA hit.
Now it worked again and I was happy.
But behold I installed the 4.4.2 update and root is gone again and I can't get it back.

Well, I tried pretty much everything: Flashing SuperSU with Wugfresh root toolkit, tried flashing CWMR over TWRP manually and then manually flash superSUv1.86 via fastboot, flashing stock recovery then wugfresh-flash superuser by koush. Everything to no avail, I still am not rooted.

So what can I do? Now I have superuser installed but no root and when I use SuperSU I don't have root and can't seem to find the app.

I would really need some help please