Alcohol and water retention/gaining water weight?

Ok so I just celebrated my 21st bday weekend and I drank a ton. I ate a little more than usual, but I didn't binge eat or anything I didn't even have a birthday cake I just had a big pasta dinner and burrito dinner that I probably coulda had in smaller portions haha. Well anyway I know I probably got dehydrated with all my drinking so I've been trying to drink a lot of water but I feel fat as ****. Last week I weighed like 134, today I'm like 141. Is it possible to gain that much water weight? Or did I really gain that much?