Trust and communication, the fundaments of all relationships;
if they're lacking in yours, then it's doomed to
be screwed. 
V
Personally, I think the possibilities of her cheating on
you is pretty low (Take my deduction with a pinch of
salt, it was based on the limited information of your babe).
Though, the odds of her being taken advantage of (when she's
drunk and high, remains very high.
There are several issues you must deal with; the first being
your own fear and insecurity. You have got to assure yourself,
instead of allowing that fear to eat into your relationship. Yes,
you heard me right - she hasn't been cheating, nor done things
against you. So get rid of your mental specter first!
Then, it'd time to communicate your thoughts with
her (gently and sensitively, of course) - let her
know your worries and concerns. And strive to resolve this problem
together, there're many possible solutions like, e.g. her cutting
down on the drinks or getting a mutual friend you both trust to
club with her. I trust you to work that out with her. Also, it's
very commendable of you not to restrict her partying life :) So
keep it up there.
Lastly, stay away from her personal diary :D You really want to
respect a woman's privacy :D If you want to know something, just
ask directly... Chances are, if a woman love you enough, she would
tell you more than what she would write in a diary :D
Good luck, amigo! Be wise and mature!
