Pain in the middle of your stomach may be due to Gastritis/Stomach ulcer
.You didn't mention whether you have taken any treatment for it and the response?
The lump in that area may be Epigastric hernia
,protrusion of fat/any content through a defect.Pain may also occur due to this hernia.It is a simple problem.It is completely curable
But,please consult your surgeon and get it diagnosed.
All the best