Q: "Ghosttouching"

Hello!

So i own a Ipad mini 2 16gb (cellular+wifi) black model. And recently my ipad have started "Ghosttouching".

I Am running IOS 9.3.5, i tried updating to IOS 10.0.2. The update went sucessfully but the ipad was still ghosttouching,  so i downgraded again (since Apple still signing 9.3.5) I googled it and it could be the storage capacity that was full, I deleted all of my pictures and uninstalled most of my apps but it didnt solve the problem, so what i do now is reseting the ipad (home button+ lock button) every 15-20 minutes cause of this, is there any solution? PS. The screen is cracked from the upper left corner to the down left corner, but it should not be the problem since i know people with cracked screens and they got no ghosttouching?

I Also tried to restore it but didnt solve it either?

Help!