析构函数导致程序崩溃

我真的在为将析构函数与复制构造函数一起使用的概念而苦苦挣扎。如果我不使用析构函数，代码可以正常工作，因为它会自动完成。如果我这样做，我会收到一个错误，说"调试断言失败！"和"表达式：_BLOCK_TYPE_IS_VALID（pHead->nBlockUse）。

但我希望能够理解如何使用析构函数。这是下面的代码，我将非常感谢帮助解释我做错或需要做的事情！
类矩阵 {

private:
    int M;
    int N;
    double *data;
public:
    Matrix();
    int getM() const { return M; }
    int getN() const { return N; }
    //CONSTRUCTOR
    Matrix(int sizeR, int sizeC,double * input_data)
    {
        M = sizeR; //Rows
        N = sizeC; //Columns
        data = new double[M*N]; //creation of 1D array, uses m&n values
        cout << "nMatrix::Matrix(int sizeR, int sizeC, double * data_value) is invoked...nn";
        //ENTER DATA INTO MATRIX HERE:
        for(int i=0; i < M*N; i++) //Loops for every data entry into 1D array, uses r&c as referenece to
            data[i] = input_data[i];//Accesses each value at specific location, inputs value 'val'
        for(int i = 0; i < M*N; i++) //Loops for every data entry into 1D array, uses r&c as referenece to size
            cout << data[i] << " ";
    }
    //get function uses row and column from user
    double get(int i, int j)
    {
        return data[i*N+j];
    }
    double set(int i, int j, double val)
    {
        data[i*N+j] = val;
        cout << "nnNEW MATRIX: ";
        for(int i = 0; i < M*N; i++)//Loops for every data entry into 1D array, uses r&c as referenece to size
            cout << data[i] << " ";
        return val;
    }
    Matrix(const Matrix& oldMatrix)
    {
        cout¸<< "nMatrix::Matrix(const Matrix&) is invoked....";
        M = oldMatrix.getM();
        N = oldMatrix.getN();
        data = oldMatrix.data;
        cout << "nn";
        //ENTER DATA INTO MATRIX HERE:
        for(int i = 0; i < M*N; i++)//Loops for every data entry into 1D array, uses r&c as referenece to size
            cout << data[i] << " ";
    }
    //DESTRUCTOR
    ~Matrix()
    {
        //delete data
        delete [] data;
        data = NULL;
        cout << "nnMatrix::~Matrix() is invoked...nn";
    }

};
int main()
{
    int sizeR, sizeC;
    double val;
    cout << "Enter No. Rows: ";
    cin >> sizeR;
    cout << "Enter No. Columns: ";
    cin >> sizeC;
    double * input_data;

    input_data = new double[sizeR*sizeC];
    //INPUTS VALUES TO ARRAY
    for(int i = 0; i < sizeR*sizeC; i++)//Loops for every row
        input_data[i] = i;
    Matrix M1(sizeR, sizeC, input_data);
    cout << "Enter row that value you are after is in: ";
    cin >> sizeR;
    cout << " & now the column that it is in: ";
    cin >> sizeC;

    cout << "Change value: " << M1.get(sizeR, sizeC) << " to:";
    cin >> val;
    M1.set(sizeR, sizeC, val);
    //calls copy constructor
    M1 = Matrix(M1);
}