My linked-list node removing function causes other parts of my program to crash

I'm encountering a weird error in some homework that has me making a stack with a linked list. All functions in my program work perfectly, even in the beginning when I have no nodes, or after deleting a few. But when I make nodes and delete them all so I'm back to zero, then every function causes a crash. I've tried researching the problem, but the solutions I've found look almost identical to what I've already got, so obviously there's something critical I'm not seeing.

Here's the node removal function (the one I suspect to be the culprit in all this)

void remove(node** root)
{   
    node* temp = *root;
    node* previous = 0;
    if(*root)
    {
        while((*root)->next)
        {
            previous = *root;
            *root = (*root)->next;
        }
        delete *root;
        *root = temp;
        if(previous)
        {
            previous->next = 0;
        }
    }
    else
    {
        std::cout<<"cannot delete items from empty list\n";
    }
}

Here's the node insert function

void insert(node** root)
{
    node* temp = *root;
    if(*root)
    {
        while((*root)->next)
        {
            (*root) = (*root)->next;
        }
        (*root)->next = new node;
        (*root)->next->data = getnum();
        (*root)->next->next = 0;
        *root = temp;
    }
    else
    {
        (*root) = new node;
        (*root)->data = getnum();
        (*root)->next = 0;
    }

}

I'm fairly sure that the issue is somewhere in the code I linked, but just in case it's not, here's a pastebin to the full assignment http://pastebin.com/AWtG4qjD