I was bitten by a tick on my genitals a couple days ago and now there is a lesion. what should i do?

See a doctor!: What type of lesion? It is typical to have a small area of redness & swelling around the site of a tick bite, so this may be nothing serious, but ticks can transmit lyme disease, babesiosis, rocky mountain spotted fever & other serious infections, so it might be wise to see a doctor, particularly one who is knowledgeable about tick-borne illness (as many doctors know little about this!).

See your doctor: To evaluate whether this requires treatment of any sort.