Random thought:
Hypothetically let's say you go back in time and kill your mother on June 27, 1963 which is well before you where born. Then you would have never existed so you couldn't have gone back and killed her but in that case you would exist and could kill her thus making you nonexistent again and on and on until you come to the conclusion that if you did it then hypothetically you would exist when you should not therefore ripping the universe apart. And since the creation can never become more powerful than it's creator time travel must be impossible. So stop trying.