Galaxy Tab 2 7.0 not booting

So I have this Samsung Galaxy Tab 2 7.0, GT-P3100 with Jellybeans 4.1.2. I recently rooted it using Kingroot. It worked fine until I tried installing a custom kernel. I installed unofficial miui v5.4 using CVM Recovery v6.0.7 I think. I clicked install from sd card and installed the .zip file. It said installed after a few mind. I then clicked reboot device now. It started booting and showed a new boot image, which I thought was normal. But the image wasn't fitting in the screen. I waited full 30 mins and it stayed there, a light coming and going as a logo. Nothing happened, so I pressed the key combination of power button + volume up button for 5 seconds and it started again, showing the new symbol. It has not booted after an hour and half.

Please help, I don't know what to do.

I admit I am a little new in this. But I saw a website to tomsguide.com and followed the steps with pictures.