Welcome to HCM.
You are suffering from burning sensation with urgency & frequency following sex using condom.
It is probably due to some sort of infection (may be urinary tract infection
) or irritation/inflammation to urethra
created by the condom.
Do a urine analysis preferably morning sample along with check for STD by VDRL
You can take short course of antibiotics like Tab Ofloxacin
200mg BD or mixed with Metrogyl
400mg TDS for 5-7 days along with urine alkaliser like syp Uriliser or Ston 1 etc.
Maintain personal hygiene including genital area, empty bladder in time,drink plenty of water,practice habit of urination before & after sex,use chemical agent free latex condom.