I would like to start by asking if your sessions of sexual intercourse are well lubricated? If not, please discuss with a doctor and introduce a safe and sterile lubricant.
The swelling, rash
and urge to want to urinate more often are all symptoms related to a possible infection. The fact that your sexual partner also shares the same presentation dors make it a little worrying.
Which is why I would like you and your boyfriend to visit a doctor and get physicall examined and tested for all possible sexually transmittable infections. Treatment shall be directed accordingly.
Hope this helps.