There's always this thought in my mind that I'll never find another girl like my ex.
Why don't you find another girl like her?
She was such a good girl.
Even if she was good, there had to have been a reason that it did not work out. You should not try to compare or make your current relationship the same as the one that you had with your ex.
If she won't get back with me, then I'll just have to hurt her.
That's horrible, and you shouldn't try to recreate a relationship if it didn't work. Why do you want to keep having failed relationships?