What should I do about my wife leaving the U.S. and going back to New Zealand and not talking to me now?

Talk about disfunctional.....I know this is going to sound pathetic. But here goes. I used to live in New Zealand and met a girl over there who I fell in love with and vice versa. I ended up getting removed from the country for overstaying a tourist visa (I was a resident of Australia and went to New Zealand for another girl who I no longer went out with). That was in May of 2008. I had been seeing Briar since December 2007. Well we continued our relationship via the phone and email and letters and I'm talking everyday contact, several times a day, talking on the phone for 5 hours a day, that kind of thing. She came over in September. Now before I ever met her I used to do drugs (speed) and I had a gambling problem on top of that. I know that sounds bad but its honest. Its one of the reasons I moved to Australia to begin with. I also have an MBA among other good qualities in case you think I'm a total loser right off the bat. Anyhow....when I came back home in May I started back in with the speed and the gambling and when Briar came over in September I had to be honest with her and things kind of took off from there. Still, we had a very strong foundation and hundreds of hours of communication prior to her coming. She lived with me in New Zealand for a few months etc. None of her friends or family were really that stoked to see her come over to the U.S. to begin with because I had a reputation with the drugs and gambling from my last girlfriend (also a kiwi) and I am older then Briar etc. But I can't help that we were in love. And I mean a sincere true love. To further complicate matters Briar has Chronic Fatigue Syndrome. Don't get me wrong she is a normal intelligent beautiful girl with a lovely personality and she really brings out the best in me. I totally love her. Totally. But I screwed up while she was here. First of all we went to a Fergie concert, one of Briar's favorite musicians. My mom hooked us up with the tickets and we were totally planning it and looking forward to it. Well she was really sick the couple days prior to the concert and feeling really bad the day of. So I did a bad thing and let her have some speed. She took it with water right before we got to the show and voila she felt fine. If you don't believe look this up, but they actually prescribe methamphetamines to people with CFS so I wasn't doing it to get her hooked on drugs or anything like that. Misguided yes deliberately trying to screw up the girl I love....no. Anyways she ended up loving it which I hated because I have already been in two prior relationships with girls where we were both doing meth and they just don't work. So I didn't like her being on it. But....for the first couple months it was like a miracle for her whenever she felt like crap she did it and pretty soon she was doing it everyday like me. Nightmare. I had a job where I was making 75k a year as a Senior Accounting Manager for a clothing company and where things really started to get bad was my gambling. I was bringing in like 2500 every two weeks and just blowing it all at the casino. We both lived at my parents house (I know I know ....LOSER) and things started to deteriorate. Briar hated the gambling and the drugs made her seem more annoying to me always complaining etc. I felt bad even as it was all happening but kind of powerless to do anything about it. It just felt like things were heading downhill. But the love was still there. And I mean that. I really truly loved her and I know she really truly loved me. But the girl is from New Zealand, she's in America for the first time, I'm leaving her at home alot of nights to go to the bloody casino where I'm obsessed with getting my money back or some stupidness. I end up losing my job and my sister commits suicide in February and wow its all just a mess. Eventually Briar has had enough and I don't blame her. She misses her mom and all of her family and friends and they miss her too. And I'm not showing her any good reasons to stay. I'm just screwing everything up self destructively but man......So she leaves and I am heartbroken beyond belief as I knew I would be and as I deserve to be. But still.....we had a good relationship and we are married by now. We got married in December. Its June when she leaves. For the first month she is gone I don't change a thing. I'm lost. Finally I start to come out of it and I get off the drugs and I bar myself from the casino. Briar and I are talking about when we reunite whats going to be different etc. The love has never died. I need that to be understood. I know with all my heart that she loves me and I love her. And I'm capable of showing her. I broke alot of promises while she was here but I really want the chance to make amends to her. I realize that drugs are not the answer and I don't even want to be on them anyway. I screwed up. But I've never wanted a second chance more then I want one with this girl.