Brenda
You are not alone. Unfortunately I know all about it, since I am incontinent myself. Since my late childhood/early teens, I have not been able to hold it like you are supposed to and have had to wear protection since then.
My urges come suddenly and I have very little bladder control.
However, it did not take me long to decide to not let it stop me in living my life in any way and today I find my "underwear" to be both practical, comfortable and actually quite sensual. I also found that none of my girlfriends have bothered about it, one even liked it, and it has not stopped me in my day.
That said, I have no problems understanding your desperation when you could not find a private place to let go - it is truly terrible.
Still, Keira has a point - even if you had peed in public, hardly anyone would remember you afterwards since such things happen.
Again, you are not alone
Hugs and smiles,
Kathy