Thanks for your query,based on the facts that you have posted it appears that you have infection of the terminal pert of urethra and external urinary meatus
) due to contact with your inner wares .
Please get your routine urine test and urine culture done to find out the organisms causing this infection and antibiotics to which they are sensitive to.
Please take broad spectrum antibiotics like Cefexine along with urinary antiseptic like Nitrofurantoin
twice daily and urine alkaliser thrice daily.Later on switch on to appropriate antibiotics as per culture report.
Get the prescription of medicines from your family Physician.
Ensure to drink more water.To keep your urine dilute This will help to control dysuria.
Ensure to wash your genitals with warm water twice daily and apply topical antibiotic
ointment like Neosporin