I am so sorry to read this, and to know that you or anyone is in this much pain. Alcohol can't stop your pain, it only delays and intensifies it down the road, but I think you know that. I don't know why you're hurting or what's wrong - there is no advice I can offer except talk to someone. Please. A friend, a pastor, a counselor, family, someone you trust. Talk about why you're hurting and what you feel about yourself, and if you can, do it before you start drinking. And listen to the good things, the positive things, they offer about yourself.
You do matter. You do not deserve to be miserable. Everyone needs help sometimes - let someone help you. If you don't know that someone, reach out. You are good enough.
If good thoughts and belief from a stranger behind some anonymous computer screen offers any help at all, you've got them. I've seen your posts around, seen you offer comfort and help and kind words to others. You care, and you matter.