For over a yr i've had extreme pain urinating when starting to urinate it feels like pressure on the inside to get started then unreal pain while urinating then aching and throbing of outer vagina i've had my urethra stretched before a couple yrs ago?

Urethral stretching (dilatation)m is rarely done these days. But there is a possibility you might have a stricture( narrowing of outer urinary tube). Call the MD who did the stretching for the reason and if you had it you might need to be stretched again. In the meantime drink water, sit in a warm tub and take OTC Azo pills. If symptoms persist see a Urologist ASAP. Hope you feel better