Will I ever get the pay off?

background: obsessive personality, determined to lose 6 pounds by July 18 beach vaca and willing to do whatever to reach it.
Logged 1200 cal (healthy cals, balanced, lots of fruit and veggie)
Exercised like never before. Sweated buckets, drank buckets. Ate some exercise cals back but not all.

End result: GAINED WEIGHT

Okay so this is probably water weight or muscle gain.

My question is where to now. Don't want to repeat last week. Still want to lose. It has now turned into 9 lbs with the three gained.

When (specifically how soon) will I get the pay off of this past week. Will it ever pay off?

I know I need to be patient. Just wondering though when that new muscle starts to burn fat. Should I continue with strenuous exercise or scale back?

Thanks for any advice.