mike_no gives excellent information and explanations! I'll tell you that I one hundred percent agree! This is not a risk for HIV.
You weren't at risk for transmission, usage of condom ensured your safety, urethra was covered at all time during intercourse, that was intended application of condom and it did that efficiently.
First up, assuming CSW is HIV positive is a product of assumption, which directly points towards anxiety, since you know that you suffer from irrational fear caused due to anxiety, it wouldn't be a bad idea to see a therapist and treat the real cause of concern which offcourse isn't HIV but maybe OCD though.
HIV can't infect outside of body, thereby having body fluid touching some part of your penis is not going to infect you as it can't miraculously crawl up into the tip of your penis, even if it somehow does, it wouldn't be able to infect since contact with the outside environment would render it infectious.
All your symptoms are probably psychosomatic, there is no real cause of concern. Please do consider seeing a therapist, refrain from reading about HIV and it's symptoms on the internet to avoid making things worse for your mind.
Testing is not recommended.