I have a really sore itchy rash on my anus looks like swollen bites with a red rash what can i do?

Steroid cream: You can start with an over the counter cortisone cream twice a day. If that doesn't help, see your doctor.

Rash on anus: This can't be diagnosed with the information that is available. A history, physical examination & other studies may be needed to determine cause/causes. Once accurately assessed a treatment plan can be developed.