Stomach pain after drinking

Hello, please, someone help me. I have anxiety, and I tend to overthink and panic easily. I am currently shaking because I am extremely worried. I also have trauma related to medical emergencies. 🙁

My older brother drank heavily for four consecutive days. He would drink, sleep for only 4–6 hours, and then start drinking again. During his second drinking session of the day, he could consume around three 509 mL bottles of Red Horse beer. Red Horse has an alcohol content of approximately 6.9% ABV.

He probably drank 2–3 times a day over those four days. He barely ate anything during that period, and whenever he did eat, it was only very small portions. He was mostly drinking alcohol.

His last drink was on September 19 at around 11 AM because he had to work that evening.

At around 9 PM that day, he experienced severe stomach pain, which he described as acid reflux or hyperacidity. He also vomited green-colored fluid once, but it only happened that one time.

His fever and vital signs were normal. However, he did not urinate for approximately 14 hours. He eventually urinated, and the amount was quite large.

The following day, September 20, we took him to the doctor. He was prescribed medication, but his stomach was still hurting. The doctor advised us to have a follow-up checkup after one week.

Is this really how these situations are usually handled? Should we simply wait for the follow-up appointment even though he is still experiencing stomach pain?

I am extremely worried because of my anxiety. I keep imagining the worst-case scenarios, and I am having a hard time calming myself down.

Here are the doctor’s findings and prescribed medications: (I will attach them below.)

I would really appreciate any advice, suggestions, or similar experiences from people who may have gone through something like this. Thank you so much.