Hi Fewer Months Ago, Inner Thigh_buttock Skin Become Red And

Hi
Fewer months ago, inner thigh_buttock skin become red and have burning sensation but after some days it went out. Then after Occasionally it comes and goes off. But from 3 - 4 months it forms a hard lump in inner thigh about 1-2 inch extends from buttock (inner thigh) to middle line below scrotum. I'm consulted my doctor they give me some antibiotics (penicillin tablets) after that lump become smaller and redness is almost gone and pain is also reduced but hard lump is still present in small size with little bit soft in the middle but it has hard boundary. And even after taking antibiotics several days it is not curing fully. Please help me