Recent, Inexplicable Pain After Drinking

I have been a pretty heavy drinker a while. I’ve cut back a lot over the past few years but when I do imbibe, it’s usually 4 or 5 stiff drinks over the course of like, 3 hours. The past 2 times that I’ve had liquor, I’ve gotten extremelyyy sick the following day. It wouldn’t be weird, obviously I’m hungover, BUT I’ve NEVER gotten physically ill after drinking. Like, I haven’t thrown up from drinking in a solid decade. No other factors have changed (no new meds, not a new type of drink, etc.)

Any thoughts on what the issue might be? Could this be an ulcer or something?

Thanks!