Sensation in upper left abdomen.

Hi Doc, approx a year ago while driving home from the hospital after being diagnosed with a lung inflammation (coughing up phlegm for 2 months straight) I suddenly felt this blow just below left rib cage in the abdomen. It felt like something either snapped or penetrated followed by a vacum feeling. I got a bit dizzy but it all went away fast. It's wasn't painful at all but I immediately felt like stretching. My dad and I had a few too many drinks the night before. And from that day on, everytime I lay flat, I have this heavy sensation in that area, as if something is resting on top. I turn to left or right and it goes away. Only when I lie flat do I get that bloated feeling. Next day I had an ultrasound, bloodwork and chest X-ray where they found a slight enlarged liver. It's been a year, the feeling is still there, no change. I had a new x-ray last week where they found "nodular opacity in left hilum". I've smoked for a few (5-6) years in my life. I exercise regularly. Thanks you Doc