Operating system crashing as well as Apps, occasional cellular loss

Iphone 6

After updating to IOS 9.2.1 I noticed my phone was crash happy,but only to a minor annoyance. I lived with it. Weeks later and the cellular goes out (searching) and I end up having to do a reset from the phone ( Itunes wouldn't cooperate) I finish this and phone comes back with cellular, but its still crashing (crashes to apple symbol, but not a full restart.. its quick restart)

I get home make a backup, and do a restore, first problem is the phone cant use the backup I had made, tells me it was corrupt. I install as new phone, phone boots up and says it cant activate through itunes. This requires me to do a restore again but this time as a new phone.

Anyhow.. Cut to the chase, this phone has been crashing a lot, both in apps and in operating system. The only other symptom is the cellular loss that occasionally happens. Another new symptom was I was using GPS to find the AT&T store and on a prompt it froze, and was flashing back and fourth, couldn't get off the screen, just had to hard reset)

I will also say, this phone was never dropped, dunked or jailbroke. I also tried to restore back to 9.2.0 and Itunes would not allow me even though I used the official file from them. The amount of restores Ive gone through on this phone leads me to believe its hardware.