Monday somehow equals drunk??

Ewwwww I am a fucking mess and so tired! How is it all weekend I keep it pretty low key but somehow on a Monday night I get shit faced and hung over for work on Tuesday? Do you know what torture it is to concentrate on the morning commute when all you want to do is vomit all over yourself? In my defense my girlfriend came home from Chicago to visit. I officially want to die! I feel for my work because the normal 2-3 hours of work they will get out of me a day has gone to zero. I feel like a piece of shit that was dragged in a ditch and dried in the sun…..