Think this can happen if it is indeed too vigorous. Things will swell when that is the case in response. I would say that you may just want to skip the attempt at sex when drunk or not drink so much to combat this situation.
I agree with/ both GuitarRox & auntiejessi that you should prbly try to moderate your drinking a bit. Not only for this prblm, but for your overall health, and also, excessive alcohol use is a factor for many men who later develop ED, so if you want to retain good sexual function as you get older, my advice is to cut back a bit.
As for this temporary swelling, that has happened to me occasionally from either extended Intercourse or masturbation. I noticed some swelling & discomfort the next day, but it cleared up within a day or two. What I DON’T know is what doing this repeatedly would lead to - in my case, it only happened occasionally & cleared up on its own. If you were to continue this, for example 2 or 3 times a week over several years, I’m not sure whether some permanent damage could occur. Im inclined to think it most likely would still clear up if you give it a rest for a couple days, but if I were you, I wdn’t wanna risk it. As guys, one of the most terrifying things for us is the thought that we cdn’t perform sexually.
Hope this advice is useful...