Newline-terminating input loop not exiting in C - c

Question

I'll preface this with the fact that this is for a homework assignment, so I'm just trying to understand what's going wrong not necessarily exactly how to fix it. I'm working in C, taking a name and grade from the user to create/manipulate structs and use a stack. This while loop won't exit and it isn't reaching the testing print statement at the bottom. line, name, cGrade, and fullData are all character arrays, maxGrade and numGrade are both double variables, s is a stack and item is a void*:
while ((fgets(line, SIZE, stdin)) != NULL && line[0] != '\n') {
if (sscanf(line, "%s %s", name, cGrade) == 2) {
numGrade = atoi(cGrade);
fullData[0] = 0;
if (numGrade >= 0 && numGrade <= 100) {
strcat(fullData, name);
strcat(fullData, " ");
strcat(fullData, cGrade);
printf("Added %s\n", fullData);
item = name;
push(s, item);
if (numGrade > maxGrade) {
maxGrade = numGrade;
}
i++;
} else {
printf("ERROR: Grade must be between 0 and 100\n");
}
}
printf("Outside if: line[0] = %c", line[0]);
}
Edit: adding a screenshot of the output
Screenshot of output
Edit: Adding push code
void push(stack s, void* item){
stackelement* e = malloc(sizeof(stackelement*));
e->contents = malloc(sizeof(void*));
e->next = malloc(sizeof(stackelement*));
e->contents = item;
e->next = s->top;
s->top = e;
}
Here's the struct definition as well. I was given this for the assignment so I'm not allowed to change it.
struck stackelementS {
void* contents;
struct stackelementS* next;
}
typedef struct stackelementS stackelement;
struct stackS {
stackelement* top;
}
typedef struct stackS* stack;

Answer 1

It ended up being the simple fact that using sscanf doesn't include the escape character \0 in the returned string which I assume was messing up some of the string functions. I added a char *end; *end = '\0'; and used strcat() to append it to the name and cGrade. I fixed some of the errors suggested in the comments and it cleaned up the code a lot.
Here's the fixed code:
while(fgets(line, SIZE, stdin) != NULL && line[0] != '\n'){
if(sscanf(line, "%s %s", name, cGrade) == 2){
strcat(name, end);
strcat(cGrade, end);
numGrade = strtod(cGrade, &ptr);
if(numGrade >=0 && numGrade<= 100){
push(s, line);
printf("Added student %s with grade %s to the stack\n", name, cGrade);
if(numGrade > maxGrade){
maxGrade = numGrade;
}
i++;
}
else{
printf("ERROR: Grade must be between 0 and 100, please re-enter the information\n"); }
}
}