I hope your OK brother.
Now look, I've been dreading the day if someone told me that.
Thing is, about you blocking her...well there must have been a reason you did so - I won't ask, but if there was a reason, then I don't see the need to feel guilty.
As they say...shiz happens.
If you wanted to be in contact with her etc, then you wouldn't have broken up in the first place - put it that way.
Long story short, another life is lost in this miserable world, and the world hasn't become a better place. But you should not blame yourself, feel guilty, or feel that you did something wrong.
Missing her, is not a crime, and is completely natural. Even if a friend of mine, be it girl or guy passed away, I would cry my heart out.
Be strong brother.
R.I.P to your ex.