Buggy implementation of a linked list

list.c

#include "List.h"
#include <stdlib.h>

typedef struct ListElement
{
    int value;
    struct ListElement* next;
} ListElement;

typedef struct List
{
    ListElement* head;
} List;

typedef struct Position
{
    ListElement* position;
} Position;

List* createList()
{
    return calloc(1, sizeof(List));
}

void deleteList(List* list)
{
    ListElement* position = list->head;
    while (position != NULL)
    {
        list->head = list->head->next;
        free(position);
        position = list->head;
    }
    free(list);
}

void deletePosition(Position* position)
{
    free(position);
}

void add(List* list, Position* position, int value)
{
    ListElement* newElement = calloc(1, sizeof(ListElement));
    newElement->value = value;
    if (position->position == NULL)
    {
        list->head = newElement;
        return;
    }
    newElement->next = position->position->next;
    position->position->next = newElement;
}

Position* first(List* list)
{
    Position* positionFirst = malloc(sizeof(Position));
    positionFirst->position = list->head;
    return positionFirst;
}

Position* next(Position* position)
{
    Position* newPosition = malloc(sizeof(Position));
    newPosition->position = position->position->next;
    return newPosition;
}

bool last(Position* position)
{
    return position->position == NULL;
}

int get(List* list, Position* position)
{
    return position->position->value;
}

list.h

#pragma once
#include <stdbool.h>

typedef struct List List;

typedef struct Position Position;

List* createList();

void deleteList(List* list);

void deletePosition(Position* position);

void add(List* list, Position* position, int value);

Position* first(List* list);

Position* next(Position* position);

bool last(Position* position);

int get(List* list, Position* position);

main.c

#include <stdio.h>
#include "List.h"

int main()
{
    List* myList = createList();
    add(myList, first(myList), 1);
    add(myList, first(myList), 2);
    for (Position* i = first(myList); !last(i); i = next(i))
    {
        printf("%d ", get(myList, i));
    }
}