Why do i get a burning sensation in my penis when i smoke weed ? i think i have epididymitis ...

Burning sensation: burning sensation when urinating may be a sign of urinary tract infection, but I am not sure that marijuana can cause this sensation. Epididymitis is an infection/inflammation of the coiled tube that is behind the testicles, this infection is usually due to chlamydia/gonorrhea and antibiotics such doxycycline 100mg twice daily plus ceftriaxone 250 mg once is needed to treat it

See your doctor : Dysuria is a painful sensation when urinating. The most common cause of this is an infection (urethritis). See your doctor for a physical exam and lab work. It is rare for cannabis to cause dysuria. You could have a sexually transmitted disease that needs to be diagnosed and treated. Best wishes!