Here's someting I did when I tried to stop cutting. I did the "butterfly method". When you have the urge to cut, draw a butterfly where you want to harm yourself and name it after a loved one, or someone that wants you to get better. If you cut, the butterfly dies. You have to wash it off. If it wears off (and you didn't cut), it is released into the wild to be free. whatever floats your boat) all over where you would've cut. When you're done, count the lines. That's how many scars you won't have. If you wanna be loud about whats bothering you, try writing a letter to yourself in a letter, once you are done expressing yourself, seal it into an envelope and either throw it away or keep it, the choice is up to you. Also go somewhere you cannot cut yourself, If you're at home, go lie on your bed. Bring your phone and a pen and paper with you but nothing else. Sort of like giving yourself a grown-up time out. If you're not at home, find a seat out in the open. A park bench, a lobby chair, and plant yourself there. Right now is all about distractions. If you can make a phone call, do so. You don't have to tell the other person on the line the issue right now, but talk to them about something. Anything. They'll take you away from this moment.
As for the drinking, Set a drinking goal. Choose a limit for how much you will drink. Keep a "diary" of your drinking. To help you reach your goal, keep a "diary" of your drinking. .Watch it at home. .Drink slowly. Take a break from alcohol. All this is normal to do when you are happy, it's become apart of you and it doesn't matter if you are happy or sad. I hope you can overcome these things, it's not going to be easy. But you are brave enough to do it! I believe in you.
It's hard to know what's going on for you without knowing your background but for me I often feel those selfharm tendencies creep in more when I'm happy because I'm fearful of it. Fearful of really feeling it because the higher you rise, the further you have to fall. Either way you should get help for this, looking at what is causing those feelings and trying to work through those issues because you do deserve to be happy.