How do I edit my code so that I may output the frequency of TWO specific characters input by a user? (C Language)

I have tried for hours to edit this code to work the way I want it to. I am meant to code a program to track the frequency of how often an underscore '_' and an exclamation point '!' appear in a sentence input by a user: _Hi_there!!!

Specifications that must be used and/or not deleted -This function prototype must remain unmodified: -The getchar() method must be used to hold the value of the sentence input by the user.

Now I have this code after hours of struggling to get a proper output:

#include <stdio.h>

int num_count;
int num_exclamation_count;
char ch;
char s[1000]; 
void count(int* num_, int* num_exclamation)
{       
    int i;
    for(i = 0; s[i] != '\0'; i++)
    {
        if((s[i] == getchar()) && (s[i] == '_'))
        {
            ++num_count;
            *num_ = num_count;  
        }
        else if((s[i] == getchar()) && (s[i] == '!'))
        {
            ++num_exclamation_count;
            *num_exclamation = num_exclamation_count;
        }
        else
        {
            continue;
        }
    }

}

int main (void)
{
    int num_user, num_exclamation_user;
    printf("Enter a sentence: ");
    do
    {
        ch = getchar();
    }while(ch != '\n');
    count(&num_user, &num_exclamation_user);

    printf("There are %d underscores and %d exclamation points in the 
    sentence.\n", num_user, num_exclamation_user);

    return 0;
}

The output I get is as follows:

There are 0 underscores and 0 exclamation points in the sentence.

I tried every variation of while or if or do-while statements I could conjure in my mind or find available online and I get nowhere but further away. If someone could thoroughly explain how I arrange which conditional statement/loop with the getchar() method and necessary variables, that would be awesome. Open to criticism as well if I blatantly screwed something up or passed over an obvious issue, do not be scared to hurt my feelings. I only want to learn and will be my only mindset as I am assisted with this problem.

Thank you.