Found this lump in my groin area. At first it was a red lump and yesterday I discovered a huge change in it. Do you know what it is?

No I do not. But, a guess would be it may be an abscess or a boil/carbuncle, or maybe an infected hair follicle (folliculitis). Any lesion like conditions should really be assessed with a clinical exam to get the definitive diagnosis to assure the correct treatment occurs, best wishes to you.
No but discuss MD. You need an evaluation and possible imaging to determine what this could be.