Pain in right foot due to lump. Burning, throbbing pain while walking. Obese and have stress fractures. How to control pain?

I have been having a lot of pain on the outside of my right foot , in the middle. There appears to be a lump there and it is very painful. It hurts to walk and often I get searing burining pain from that lump and it throbs. I have not done anything to cause injury although I am suspicious I may know what it is. A bone spu on a stress fracture , perhaps? I am morbidly obese and do occasionally have issues with stress fractures in my feet , but this spot is the worst I ve had. It hurts to even touch it. Is it possible a switch from tight shoes to loose sandals may have allowed this to happen and what can I do for it beside wear hot, tight shoes from morning to night. Like I indicated, there is a bump, very painful at all times and occasionally searing, burning, throbbing pain will emit from it for no reason.