Hi Jing. I know just how you feel.
I have just over 2 weeks to go to mine and I've been able to do no training at all for the last 3 weeks, and no sign of that changing. Looks like I'm going to be walking the whole thing. I'd have done better with no training at all - at least I wouldn't have been injured
My foot is finally getting better but very slowly and I ran half way across the road last night to avoid being run over and even that made it noticeably worse. It's soooooo frustrating.
Is there another 5k run you can do later in the year, to have something else to train for? I think there's an Adidas one in September in London and a couple of other places, if it isn't full up already.