Motorola Moto X (2014) — Hacked phone?

Someone is using my phone identity. It started freezing up and then when I powered it up it would go through a system boot and then shutdown as soon as you tried accessing the phone. I did upload a phone tracker app for my son's phone but never used it or activated his. I also think someone is sending texts that show up from my phone. I get texts from a voip number but call logs say the text comes from MY phone. I activated another phone since then. Also, my Google account has shown suspicious activity. I have changed passwords and am getting notifications for attempted logins. Any info would be helpful...