If that cicumferential "swollen blood vessel" is firm, not particularly tender, and maybe even whitish in color, you are probably dealing with lymphangitis. This will resolve on its own. You can try a non-steroidal like ibuprofen (if you do not have any contraindicatons).
The cause is unknown. If it persists for more than a few weeks, or it is enlarging, see a urologist.
I have the exact same symptoms. What happened? Did it clear up or did you have to see a doctor?