Need some active encouraging MFP Friends!

I lost 8.8 pounds in 23 days....I WAS feeling positive until I went to weigh in on Monday I gained three pounds from my weigh in on that prior Friday and my self-defeating emotional pattern begin to kick in and I just cried, cried and cried and since then I’ve had four/five bad days now but I’ve still been logging in my food diary online. On top of all that my knee is in so much pain I’m limping, and can barely stand so I haven't been to the gym because I’m scared of what my knee might do. I plan this Saturday to go swimming maybe that will help. It's that girl time of the month soon so all I'm craving are sweets, sweeets,sweeeeeetttttttttts! I love my healthy journey I know I can do it, I'M NOT GIVING UP! I MUST CONTINUE TO REACH MY GOAL OF 50POUNDS BY NOV. ANY ADVICE?