I felt better every morning after binge drinking every night?

I (M18) started drinking heavily basically the day I turned 18. In fact, I only stopped because of the ridiculous amount I was spending on said alcohol and the fact that I was getting fat as fuck. My daily routine was (and basically still is) work 12 hours a day (tradie), get to the work house, eat – shit – shower, drink half a bottle of smirnoff vodka (500ml), act like a retard and fall asleep. Since I’ve stopped, which has been about a month-ish (and as said, for mostly financial and waistline reasons) I’ve felt like shit every morning. Does anyone know why? Literally tempted to start again but mb in lower quantities. I have lost weight so I have less of a tolerance now.