Hi I Fell Jan 8th And Was Checked My Doc

Hi I fell Jan 8th and was checked my doc with xrays and found nothing except for old injuries due to surgery in 1980. I am 59 over weight. My problem is I reach down to get a knife off the floor and had a hard time getting to the car. It fells like a spasm and does not happen unless I try to get up. The pain takes my breath away. I am taking flexarel which doesnt seem to be helping. What do I do next.