iphone screen froze

OK my mf iphone screen froze! Is it because I got sand in it and then washed it off in the lake after? Well idk because that happened like a month ago. So the screen froze on "trust this computer?" and i'm pressing the buttons "yes" and "no" and it wont do anything so I go to restart it but the stupid thing wont let me slide the turn off button thing so I held the buttons down longer and then it made the sound like it was going to call 911. So basically what i'm saying is i'm listening to sad songs rn and crying so if anyone could help I will give you a kiss kiss.