Suggest Treatment For Persistent Lump Near The Pubis

I have a golf ball-sized lump on the left side of my pubis, about half-way between my vagina and inner thigh. I have been taking 500 MG Amoxicillin since Friday afternoon for a dental infection. The lump came up either on Saturday or Sunday, is red, warm and painful, especially when I walk. No head, no drainage. Slight fever last Thursday, probably due to the tooth infection. I do not shave in that area. I am female, 54 years old, and otherwise healthy. Many years ago, when I did shave that area, I did use to get the ingrown hair cysts that my gyno had to slice and drain; however, have not had this in a very long time and, again, do not shave in that area. This time, the lump is much larger. I have read to try sitz baths, which I will do tonight. Is the Amoxicillin good to be taking if there is infection (since I am still taking it for my tooth infection)? Any other suggestions? Thank you.