Thank you for your query at DoctorSpring.com
Since you wore a condom, I won't be worried about any STIs here.
However, because of the drinking, you did develop gastritis, which can cause most of the symptoms making you gassy, upper abdominal pain, e.t.c
I would advise you a course of Cap. Omeprazole twice daily for 2 weeks, and Syp. Mucaine gel, if you feel too bloated and gassy.
Please take these medicines for 3 days, and let me know if it is improving.
Otherwise we would need a CT Abdomen, to rule out any liver enlargement or hepatitis.
Feel free to discuss further,