What Causes Stomach Pain After Having A Late Meal?

I am having very painful mid section stomach pain since waking and again yesterday. I drink a lot and when I do, I have a late meal and go right to bed. In the last 4 months I have this stomach pain when I do that. It is hard to find relief. Two days ago I drank and pork chops and salad and went right to bed. Woke up with the pain, but it went away late morning. Yesterday I didn t drink. Had a protein shake in the AM, a bagel and cream cheese in the afternoon and left over pork and [pasta and went to bed 2 hours later. Today the pain is very sever and won t go away. I question if I have chronic pancreatis, byt maybe because I have been drinking for most of my life. It seems more acute, If I don t drink and eat late I m usually ok. But wjen I do I wake up with this pain. What is confusing is that during the early and middle of my sleep I feel fine. It just seems to come on in the last few hours before I wake. Anyway, I know I need to stop drinking and change my eating habits. I can do this for short period of times, but I revert back. What should I do tomorrow besides not drinking. Also how do I determine if this is acute or chronic. Thanks, Ed