I'm not sure you're going to find the answer if you're with her every single day and not giving yourself a chance to be alone. If you give yourself some space, learn how to enjoy time for yourself, it might become more clear what you really want. The truth is you're NOT lost without her. It may feel that way but it's not true. You managed before you met her, right? :-)
Can you try attending some AA meetings when you're bored with nothing to do? You might meet some very cool sober people there who you can call and do things with when your gf is at work or when your gf is drunk.
Good luck, Change! We all know none of this is easy.