I agree that a good amount of that weight is likely water and that it will come off, but try not to let a sense of urgency stress you out to the point that it halts any possible losses or, even worse, the increase in cortisol release causes you to gain. I've seen a lot of people here admit (in hindsight) that their stress level or losing the gained weight did impede the results of some pretty grand efforts. Once they stopped allowing this goal to occupy an unreasonable amount of time and energy both mentally and physically, the weight seemed to budge with much more ease.
Drinking lots and lots of water has always helped me shed extra water weight - but keeping electrolytes in check while doing so makes a HUGE difference in how I feel. Sodium and potassium depletion is not a fun thing!
Good luck to you, I'm eager to follow your progress.
Life is not a matter of having good cards, but of playing a poor hand well.
- Robert Louis Stevenson