In Koheles, Chapter 11:9
Rejoice, Young man in your youth, and let your heart cheer you in the days of your youth, and walk in the ways of your heart, and in THE SIGHT OF YOUR EYES, but know that for all these things Hashem will bring you to judgment.

Part of me says "if I only can do it one more time" that will save me.  Look one more time.  go to that place one more time.  I can't stand it anymore, I have to act out."  That is my addiction talking.  How do I overcome this?  I ask myself, "Do I really want to go back to secretly sneaking around, lying to my family, covering myself up so no one will see me. ?  Do I really want to go through this pain of withdrawal all over again." NOOOOOO!!!!!! 

But somehow in the past 9 years I have hit bottom 3 times. Once I let my guard down, stop talking to my friends, stop going to meetings, stop reading, it's easy to rationalize and say, "I can do this on my own."
(hitting bottom means, you do something so awful that you, yourself, could not fathom every THINKING of doing such a thing, and now you've done it)

What's the answer?  Koheles gives it to us in THE VERY NEXT POSUK.  Listen carefully.

10: Therefore, remove anger (resentment, fear) from your heart, and put away eveil from your flesh, for childhood and youth are vanity.  HEVEL!

This is the answer guys.  Remove resentment, fear and anger from your heart.  Resentment is our #1 cause of falling. Think about it.  Did you ever do this when you felt on top of the world, that the world was yours and everything was going great.  You had no worries?  I doubt it.  If you have, I'd like to hear your story.

Cheshbon Hanefesh for us means writing down 10 people, things, institutions, political parties, ideas, beliefs, values THAT YOU RESENT.  Next, for each one, write down what is causing that resentment?
(they did xyz to me, they talk too much, they're arrogant, obnoxious, SOBs, etc.).

There is the next step which makes it all go away:
3.  This affects my? ambition, self esteem, personal relationships, emotional well being.  Write down.

4. THE KEY: forget about everyone and everything involved and write down What Part YOU did to help cause the situation or make it worse.  Were you:
    a. Selfish
    b. dishonest
    c.  fearful
    d. inconsiderate

We're not talking about emotional, physical, or sexual abuse here.  those need PROFESSIONAL HELP.
We're talking about everyday annoyances that we blow up way out of proportion and it affects us.

I invite you to share because the more we see similarities the sooner we'll heal.  This exercise is key to your recovery.  Need a Jewish resource?  Cheshbon Hanefesh.

Elya,

  Yes, when we are down, and full of bad middos, i.e resentment etc, this will allow the Y"H to get a foot hold into our minds, but,

Also when everything is going really great, and we are "on top of the word" we are still not safe.  I saw in the Michtav M'Eliyahu that when people are really really happy, (I don't think he was referring to the spiritual inner happiness which is built on kedusha), but let's say you are "on top of the world" as you put it, i.e.  you won the lottery, you just made an unbelievable business deal, or as R' Dessler was referring to,  a time when everyone is really happy, this leads to frivilous behavior. Maybe Purim is an example of this. Even when we are on top of the world, the Y"H can use this to steer us into light headedness, laitzonous and this generally causes one to let his guard down. Full of anxiety, resentment etc, the menuval enters our weak minds. Overly happy, on top of the world, no worries, we tend to forget about him, and we let our guard down. He immediately jumps in.  So, I guess as the Rambam says, "The middle road is the only safe one, and either extreme will lead us to failure.