You have posted on the wrong site. Questions about HIV belong on the HIV prevention site. I will do my best to answer your questions with this reply but, if you have additional questions or follow-up they must be on the HIV Prevention site. Sorry
Your rash is not ARS but due to some other cause. The rash is only one part of the ARS syndrome and your symptoms have occurred too long after exposure to be ARS. Even if it looks precisely like the rash described for ARS, you must realize that the appearance of this rash is non-specific and many, many other things can cause precisely the same sort of rash. The list is long and includes allergies, community acquired viral infections, and many other sorts of dermatological conditions. The way to sort this out is to see a health care provider for evaluation. For me to guess over the internet would not be proper, nor would it be in your best interest.
If you remained about the exposure you describe, get an HIV test. It will be negative and then you can forget about that concern
As for your exposure, it was just about no risk. You used a condom and condoms work. The presence of a rash at the base of your penis would not change that and it is quite normal for persons wearing condoms to be exposed to their partners genital secretions on non-condom covered parts of their body. Despite these sorts of exposures, they do not get HIV or other STDs.
Further questions must be on the HIV site. Hope this helps. EWH