It didn't go away for those three weeks bud, you just reached a plateau before crashing down again. It sucks but you'll probably have a thousand of them and during that time you may even feel "invincible" just don't forget that it can all come back again and you have to keep constantly vigilant against it's return.

I'm not saying there's no cure or getting better, because I know some people that do get better, but just keep looking out for the signs that it is coming back