It doesn't happen every night by any means. In fact it's fairly infrequent (luckily). It happens less than once a month, ranging from a one month gap in between occurrences up to around 4 months in between.
When it first started happening it was very severe. I was only 15 then and I was in so much pain in the middle of the night that I woke up my parents and sat crying on the couch while they tried many things to help to no avail. The pain is only after I've been lying down. I don't think it is the result of lying in a certain position because I'm not lying in some weird way when it happens.
When it starts out, my lower back begins to hurt as if I were maybe bending it very sharply backwards (like lying halfway off my bed or something) and sometimes my upper abdomen by my lower ribs feels very tight and painful. Now I can recognize this feeling and I take some pain killers, put a pillow under my butt, take away the one under my head, and pull my knees to my chest. This is the only position that relieves the pain somewhat (it doesn't completely go away for several hours but this makes it a little better).
However before I began to recognize the starting of these episodes of pain and they got farther before I started to relieve them It got really bad. The lower back pain used to get very severe if I didn't try to make it go away in time (and it's still really bad even if I do, so just imagine) and the pain in my upper abdomen could become so severe that I could hardly move and I literally felt as if a rope were being tightened around me right there.
I went to a doctor about a year ago about this, doing my best to describe the pain as well as I could but all she said is "It's probably your posture. Try stretching out your lower back when it happens. Pull your legs to your chest and do little exercises extending one of them at a time." (Or something to that affect). That's how i came up with the way I lay to somewhat relieve the pain. I even do those little leg exercises if the laying position doesn't help enough. They help a tiny bit.
Can anyone shine some light on why I feel this way? It doesn't seem to make any sense as it it quite infrequent but very painful.