I Have Been Experiencing Pain In My Stomach - Between

I have been experiencing pain in my stomach - between my lower rib cage - at times it feels very heavy like there is something solid stuck in there and other times feels light like a hollow area/tube but taking up space in this are of my stomach. It has at times made me feel a bit nauseous (but not too bad) (doesn't feel like indigestion). I have had this occasionally for a couple of months but for the past couple of days it has been quite severe and constant. The pain has woken me up during the night, has been very uncomfortable and at times just hit quite severely - and suddenly. I don't have any medical problems or take any medication. thankyou for your help. Regards
Sue