Welcome to HCM
We understand your concerns
Your problem seems to be purely psychological if this happens even after micturation just before sexual intercourse. If we micturate just before sexual intercourse, we are sure that urine cannot accumulate in bladder so as to pressurize you in just 10 or 15 minutes. Also note the intervals of your actual urination during the day.
If you are having this problem even after the above solution, then it is surely psychological. Consult a psychologist
to have a sexual counseling session. I can help you if you desire so.
Get well soon.