Need to pee" feeling 24/7 and slightly burning feeling when peeing. have been taking antibiotics for 3 weeks, and have been checked for prostatitis. could yeast infection in the urethra cause this?

Unusual: Yeast infection in the urethra in a young healthy male would be unusual. However, common bladder irritants, such as caffeine, alcohol, and spicy foods can cause a burning, need to urinate sensation. Also, prostatitis may take a long course of antibiotics and anti inflammatoriea to resolve.

Get checked: That would be an unusual cause for your symptoms. More common would be gonorrhea, chlamydia, trichomoniasis, mycoplasma or ureaplasma, all of which cause urethritis. None of these require three weeks of antibiotics, but they do require the right antibiotics. You should see a doctor.