What Can I Do About The Yellow Pus-like Discharge And Tight Foreskin Causing Urinary Obstruction?

Sir, for the last 2 months yellowmass( puslike) accumalating between foreskin and gland) during night causing little obstruction for free passage of urine for first time. Latter passage will be normal. Also foreskin became tight and unable to retract. I am 75 years and diabitic for last 19 years. Kindly suggest remedial measures.