Phone is texting on its own typing whatever whenever I'm trying to send a message I get in my email it just keeps texting on its own I literally have to hold down the back button and talk to text what do I do

on top of that what I just wrote above about my phone just completely doing whatever it wants it's like some something or somebody is controlling my phone and I almost cannot do anything at all with my phone this is really weird I've never had something happened to me like this and I've always had iPhones I'm not sure what I'm even supposed to do because this is my only form of communication with the outside world you know out of my house so I don't have another phone and I am stuck in this is very very very frustrating when somebody help me

in right now as I am waiting for a response my phone is pushing buttons and trying to get out of this page and close different pages and add different pages and it's just adding letters and almost not allowing meh ggghsggjgaggsggkhggkdgg