lose weight

I have to lose weight now. Right now
I used to do exercise three times* a week.
Since when then I became lazy and ate a lot.
Now my weight bothers me everyday.
I know the problem, but can not make myself to start exercising now.
I feel so bad.
Now the Spring Festival is coming soon.
I must to move from now to avoid becoming a fat girl during the Spring Festival.

*The word 'thrice' is correct, but it is very uncommon.