Have you read the dillution sticky?
You must have drunk quite a lot of fluids that morning.
Use a sports drink for dillution and don't drink more than 40 ounces in 3 hour period.
I think in your case dillution will still work but only do a mild dillution. Say about 24 ounce of gatorade the morning of the UA. They may observe you this time because you failed by dillution.
In the future pickup some synthetic urine to cover your butt for randoms.
One cautionary note. If you are involved in an accident they will test you almost immediately and they may also order a blood test. SO in the future be prepared and be careful.