You will undergo countless hour of therapy moment, talking with people, addressing the issue and finding solutions in which it's just interim.
Talking about how you will overcome it easily and how time will heal everything. Truth is, when you are actually not focusing on thinking about it, the problem will just disappear and not occupy your mental space.
You thought you have made it through. No, he came crawling back into your life and now you are miserable.
Yes, you made a vow to be depressed for only a week. Time is ticking, few more days and you'd better be cheerful and bubbly.
And so you know, you've survived 2 months. Next course of action, extend the duration longer and eventually it will be long enough for you to let go and forget totally about him.
Good luck, Chen Xing.