Post Grad Stomach Problems

So I drank a ton in college and never had an issue getting drinks down. I graduated this past spring though and have considerably cut down how much I drink to on average getting pretty drunk once every 2-3 weekends, and I really don’t drink outside of those days. Since I stopped drinking as much, every time I do try to drink my stomach always ends up hurting making it difficult to keep on drinking. It makes me feel like a completely different person from who I was in college. Was just wondering if anyone else has had a similar experience after gaining a “healthier” relationship with alcohol because I’m not really seeing anything online about it