Welcome in H.C.M.
I have gone through your query regarding mouth sores, stinging pain in urethra
and discharge. Though you are treatment of your family doctor but your diagnosis is not made.
As per your symptoms you should go for these investigations-
(a) Culture & sensitivity of throat swab.
(b) Blood- CBC, Blood sugar ( F & PP ), VDRL
(c) Urine - Routine and microscopic.
-Culture & sensitivity of urine.
By the inferences of above investigations one may reach to final diagnosis that may be managed accordingly.