Just Commit Hara-Kiri

Just 24 hours ago, I felt like was gaining some control over myself. 
I began to get past the whole thing with the new girl.  I found motivation to do the little things that seem to get pushed aside when I am down.  I sent a message to the new girl letting her know that if she gets to a point where she might want to see me, she should call because I would like that.  I found out she is coming to volleyball.  There are mixed feelings about it.  I am not sure how to handle it.
Then I did stupid shit. 
I made out with someone that I probably shouldn't have.  I neglected friends that I shouldn't have. 
Today, I saw the ex wife in the gym.  This in itself is not really a big deal.  I can handle that much.  Today, however, she mentioned that she was seeing someone....a UFC fighter to boot.  This is really great for her and I am happy that she has found someone that is more her speed.  Then I think that she really is better off now that we are not together.  Yet, I am not and it is all my fault. 
The fact that she is seeing someone and seems to be happy is not what bothers me the most.  I am more pissed at you know who for the final text message she sent before I cut off all communication.  She said to me that I had to move on.  She has and so has my ex wife.  She finished with "I know all about it."  This message was pretty much the line for me.  In itself, it was below the belt and said with no other intention than to hurt me.  What really pisses me off is that she did know, and she felt that she was the one who was going to tell me because she knew it would fire me up. 
I know that I said things to her.  I recognized it and I apologized for sinking as low as I did.  She apologized too.  Then she proceeded to message me more fucked up shit.  I haven't thought about her in weeks....till today.  Then I get a card in the mail.  The intention was good.  I appreciate that she wants to be friends.  The card has fucked me up, though.  It brought up a bunch of shit that I thought I had dealt with.  This was compounded on top of the ex wife and the new girl and blah blah fucking blah.  It is all too much.

What the fuck?

I tossed aside a decent enough life because I thought I would be happier.  I began a "relationship" with someone else because I thought it would be better.  I wanted it to be better.  It wasn't.
Now I sit alone feeling alone.
I know that I need to do something.  I need to make some moves.  I need to get on the proverbial horse again.  I have to.  I can't be in this rut forever.    But how do I know which horse to ride?

A piece of advice for anyone pondering a divorce. 
When you think about leaving your wife because you think there is something better out there, take a knife and shove it into your chest.  The pain is similar, but I think that divorce is worse because that is a decision you have to live with.  The knife at least kills you.