I had my phone hacked . It is so meat up i can’t put a password back on it.

I had someone hacked my phone . Now I can’t even get the phone to put in a passcode back on the phone. I have not had it for one year or better. When they did it . Now it flashing blue all over and my screen is shrinking down . And i here other people talking in the back grown. ?? . Please help me out.i phone rang.