Drinking in moderation is always important, for both your current and future health. If you have trouble drinking only in moderation, you need to seriously think about whether you may be an alcoholic. It is important that you be honest with yourself about this. If you are an alcoholic, there are programs out there that can help you. Find a meeting in your area and start going regularly. You don't have to go it alone.
Whether or not the alcohol use is causing your pain, you need to be seen by a real doctor and get this checked out. If it is a posture issue, you may need physical therapy or a back brace to wear. You may also want to consider finding a better mattress, if the one you have isn't both comfortable and supportive (rock hard mattresses aren't better for your back, no matter what they used to say).
Good luck. I hope you get the help you need, if you need it, and relief from the pain soon.