Hey Romeos Girly,
Sometimes a relaxing weekend can turn into depressurization--and you get the emotional "bends"! Maybe that's what happened to you.
Have you been to the Chicks in Control forum here? Might be some help there as well.
Pick yourself up and get back on track! You can do it! You didn't gain a pound--that's water imbalance. Go back to your normal program and it will disappear.
As for the exercise, there is alot of exercise you can do without aggravating your shoulder--walking, elliptical without the arm motion, exercise bike... Try some of those for awhile?
Keep going!
Jay