Question for those that know about overeating and weightloss.?

I'm 21 years old, and 239 lbs. Two months ago, I weight 256 lbs. I've shed the weight so far by just eating healthy and trying to do cardio and weightlifting 5 days a week. I'm doing good except one problem. I have a severe overeating problem. It's like a relaps, once in awhile, I say screw it and somehow talk myself into eating using the justifcation that it's my last time and it's just a farewell to the junk food. For example today is the fourth day i've gone in a row with healthy eating and exercise everyday, then about 3 hours ago I god talked into having a few beers (my brother isn't very supportive of my health goals). So I had three beers and then said to myself, well, my day is shot, I might as well enjoy some food. So I had some frozen pizza snacks, a slice on bread and pepper jack cheese, four half pound bean and cheese burritos and a mcdouble hamburger. Now I'm laying here, feeling like crap feeling sorry for myself. How would you recommend I deal with this problem. Because I'm trying hard to do better, to do good, and then I go and do what I did tonight. How do I stop myself?