Default [D800] Stuck on LG boot logo

I had CM11 M6 installed. I wanted to flash this kernel called Furnace. I used the AOSP version, not sure if I should've used stock. Before I flashed it, I tried to wipe the cache. It was taking about 5 minutes so I force rebooted it. After I did that, my phone would be on the LG boot screen for about 3 minutes (before it was about 5 seconds) then I would see the CM boot screen. Overnight I tried wiping the cache again. When I woke up, I was on the lock screen. I flashed Furnace and then I was stuck on the LG boot screen. I went back into recovery and tried resetting to factory or whatever it's called and it took awhile to format /cache but it eventually did. Still, I was stuck on the LG boot screen. For some reason I thought installing a new recovery would help (I had CWM before). I pushed a TWRP recovery file for my device to my phone. I then put this command in the adb shell: dd if=/sdcard/recoveryfilename.img of=/dev/block/platform/msm_sdcc.1/by-name/recovery (recoveryfilename.img was replaced with what it was named). I rebooted into recovery from the old recovery, and on the top left it said secure booting error. I tried restarting and booting into recovery, no luck. Now I'm not really sure how to flash a new recovery because I can't get into recovery. I'm pretty sure to fix my booting problems I need to reflash CM, which will flash CM's kernel...?

Also, when I try to use fastboot commands on my computer, I get ERROR: could not get pipe properties

Can I use adb while it's in this boot state? Please help!

By the way, I'm using a mac

Edit: Looked around on the Furnace Kernel thread, I guess I used a too new version of the kernel for CM11...

Edit: Found this:, gonna try it out soon...